14. Database Access

  Module Sql

Description

The SQL module is a unified interface between pike and all its supported databases. The parts of this module that is usuable for all normal uses is the Sql class and the sql_result class.

Example

string people_in_group(string group) { Sql.Sql db = Sql.Sql("mysql://localhost/testdb"); return db->query("SELECT name FROM users WHERE " "group=%s", group)->name * ","; }


Variable NULL

Val.Null Sql.NULL

Deprecated
See also

Val.null

  CLASS Sql.Null

Description

This class is used to implement the SQL NULL value.

Note

There's typically only one object of this class: Sql.NULL , but some databases (eg Oracle) have multiple types of NULL, in which case they all inherit this class.

Deprecated
See also

Val.Null , Val.null , Sql.NULL


Method encode_json

string encode_json()

Description

Defined for use with Standards.JSON.encode , so that it formats NULL as null.

  CLASS Sql.mysqls

Description

Implements SQL-urls for mysqls://[user[:password]@][hostname][:port][/database]

Sets the connection to SSL-mode, and sets the default configuration file to "/etc/my.cnf".

FIXME

Ought to load a suitable default configuration file for Win32 too.

Note

This connection method only exists if the Mysql-module has been compiled with SSL-support.


Inherit mysql

inherit Sql.mysql : mysql

  CLASS Sql.sql_result

Description

Implements the generic result of the SQL-interface. Used for return results from SQL.sql->big_query().


Variable master_res

mixed Sql.sql_result.master_res

Description

The actual result.


Variable index

int Sql.sql_result.index

Description

This is the number of the current row. The actual semantics differs between different databases.


Method create

void Sql.sql_result(mixed res)

Description

Create a new Sql.sql_result object

Parameter res

Result to use as base.


Method num_rows

int num_rows()

Description

Returns the number of rows in the result.


Method num_fields

int num_fields()

Description

Returns the number of fields in the result.


Method eof

int eof()

Description

Returns non-zero if there are no more rows.


Method fetch_fields

array(mapping(string:mixed)) fetch_fields()

Description

Return information about the available fields.


Method seek

void seek(int skip)

Description

Skip past a number of rows.

Parameter skip

Number of rows to skip.


Method fetch_row

int|array(string|int|float) fetch_row()

Description

Fetch the next row from the result.

Returns

Returns an array with one element per field in the same order as reported by fetch_fields() . See the Sql.Sql class documentation for more details on how different data types are represented.


Method fetch_json_result

string fetch_json_result()

Description

Fetch remaining result as JSON-encoded data.

  CLASS Sql.msql

Description

Implements the glue needed to access the Msql-module from the generic SQL module.


Inherit msql

inherit Msql.msql : msql

  CLASS Sql.Sql

Description

This class encapsulates a connection to an SQL server. It is a generic interface on top of the DB server specific implementations. That doesn't mean that there aren't plenty of server specific characteristics that still shine through, though.

This class also serves as an interface guideline for the DB server specific connection classes.

Untyped and typed mode

The query results are returned in different ways depending on the query functions used: The ..typed_query functions select typed mode, while the other query functions uses the older untyped mode.

In untyped mode, all values except SQL NULL are returned as strings in their display representation, and SQL NULL is returned as zero.

In typed mode, values are returned in pike native form where it works well. That means at least that SQL integer fields are returned as pike integers, floats as floats, SQL NULL as Val.null , and of course strings still as strings. The representation of other SQL types depend on the capabilities of the server specific backends. It's also possible that floats in some cases are represented in other ways if too much precision is lost in the conversion to pike floats.

Note

For historical reasons, there may be server specific backends that operate differently from what is described here, e.g. some that return a bit of typed data in untyped mode.

Note

Typed operation was not supported at all prior to Pike 7.8.363, and may not be supported for all databases.


Variable master_sql

object Sql.Sql.master_sql

Description

Server specific connection object used for the actual SQL queries.


Variable case_convert

int(0..1) Sql.Sql.case_convert

Description

Convert all field names in mappings to lower_case. Only relevant to databases which only implement big_query(), and use upper/mixed-case fieldnames (eg Oracle).

0

No (default)

1

Yes



Method quote

string quote(string s)

Description

Quote a string s so that it can safely be put in a query.

All input that is used in SQL-querys should be quoted to prevent SQL injections.

Consider this harmfull code:

string my_input = "rob' OR name!='rob"; string my_query = "DELETE FROM tblUsers WHERE name='"+my_input+"'"; my_db->query(my_query);

This type of problems can be avoided by quoting my_input. my_input would then probably read something like rob\' OR name!=\'rob

Usually this is done - not by calling quote explicitly - but through using a sprintf like syntax

string my_input = "rob' OR name!='rob"; my_db->query("DELETE FROM tblUsers WHERE name=%s",my_input);


Method encode_time

string encode_time(int t, int|void is_utc)

Description

Converts a system time value to an appropriately formatted time spec for the database.

Parameter t

Time to encode.

Parameter is_utc

If nonzero then time is taken as a "full" unix time spec (where the date part is ignored), otherwise it's converted as a seconds-since-midnight value.


Method decode_time

int decode_time(string t, int|void want_utc)

Description

Converts a database time spec to a system time value.

Parameter t

Time spec to decode.

Parameter want_utc

Take the date part from this system time value. If zero, a seconds-since-midnight value is returned.


Method encode_date

string encode_date(int t)

Description

Converts a system time value to an appropriately formatted date-only spec for the database.

Parameter t

Time to encode.


Method decode_date

int decode_date(string d)

Description

Converts a database date-only spec to a system time value.

Parameter d

Date spec to decode.


Method encode_datetime

string encode_datetime(int t)

Description

Converts a system time value to an appropriately formatted date and time spec for the database.

Parameter t

Time to encode.


Method decode_datetime

int decode_datetime(string datetime)

Description

Converts a database date and time spec to a system time value.

Parameter datetime

Date and time spec to decode.


Method create

void Sql.Sql(string host)
void Sql.Sql(string host, string db)
void Sql.Sql(string host, mapping(string:int|string) options)
void Sql.Sql(string host, string db, string user)
void Sql.Sql(string host, string db, string user, string password)
void Sql.Sql(string host, string db, string user, string password, mapping(string:int|string) options)
void Sql.Sql(object host)
void Sql.Sql(object host, string db)

Description

Create a new generic SQL object.

Parameter host
object

Use this object to access the SQL-database.

string

Connect to the server specified. The string should be on the format: dbtype://[user[:password]@]hostname[:port][/database] Use the dbtype protocol to connect to the database server on the specified host. If the hostname is "" then the port can be a file name to access through a UNIX-domain socket or similar, e g "mysql://root@:/tmp/mysql.sock/".

There is a special dbtype "mysqls" which works like "mysql" but sets the CLIENT_SSL option and loads the /etc/my.cnf config file to find the SSL parameters. The same function can be achieved using the "mysql" dbtype.

int(0..0)

Access through a UNIX-domain socket or similar.


Parameter db

Select this database.

Parameter user

User name to access the database as.

Parameter password

Password to access the database.

Parameter options

Optional mapping of options. See the SQL-database documentation for the supported options. (eg Mysql.mysql()->create() ).

Note

In versions of Pike prior to 7.2 it was possible to leave out the dbtype, but that has been deprecated, since it never worked well.

Note

Support for options was added in Pike 7.3.


Method is_open

int is_open()

Description

Returns true if the connection seems to be open.

Note

This function only checks that there's an open connection, and that the other end hasn't closed it yet. No data is sent over the connection.

For a more reliable check of whether the connection is alive, please use ping() .

See also

ping()


Method ping

int ping()

Description

Check whether the connection is alive.

Returns

Returns one of the following:

0

Everything ok.

1

The connection reconnected automatically.

-1

The server has gone away, and the connection is dead.


See also

is_open()


Method set_charset

void set_charset(string charset)

Description

Changes the charset that the connection uses for queries and returned text strings.

Parameter charset

The charset to use. The valid values and their meanings depends on the database brand. However, the special value "unicode" (if supported) selects a mode where the query and result strings are unencoded (and possibly wide) unicode strings.

Throws

An error is thrown if the connection doesn't support the specified charset, or doesn't support charsets being set this way at all.

Note

See the set_charset functions for each database connection type for further details about the effects on the connection.

See also

get_charset , Sql.mysql.set_charset


Method get_charset

string get_charset()

Description

Returns the (database dependent) name of the charset used for (at least) query strings. Returns zero if the connection doesn't support charsets this way (typically means that a call to set_charset will throw an error).

See also

set_charset , Sql.mysql.get_charset


Method error

int|string error()

Description

Return last error message.


Method select_db

void select_db(string db)

Description

Select database to access.


Method compile_query

string|object compile_query(string q)

Description

Compiles the query (if possible). Otherwise returns it as is. The resulting object can be used multiple times to the query functions.

Parameter q

SQL-query to compile.

See also

query , typed_query , big_query , big_typed_query , streaming_query , streaming_typed_query


Variable zero

protected ZeroWrapper Sql.Sql.zero

Description

Instance of Zerowrapper used by handle_extraargs() .


Method handle_extraargs

array(string|mapping(string|int:mixed)) handle_extraargs(string query, array(mixed) extraargs)

Description

Handle sprintf -based quoted arguments

Parameter query

The query as sent to one of the query functions.

Parameter extraargs

The arguments following the query.

Returns

Returns an array with two elements:

Array
string 0

The query altered to use bindings-syntax.

mapping(string|int:mixed) 1

A bindings mapping.



Method query

array(mapping(string:string)) query(object|string q, mixed ... extraargs)

Description

Sends an SQL query synchronously to the underlying SQL-server and returns the results in untyped mode.

Parameter q

Query to send to the SQL-server. This can either be a string with the query, or a previously compiled query (see compile_query() ).

Parameter extraargs

This parameter, if specified, can be in two forms:

  1. A mapping containing bindings of variables used in the query. A variable is identified by a colon (:) followed by a name or number. Each index in the mapping corresponds to one such variable, and the value for that index is substituted (quoted) into the query wherever the variable is used.

    res = query("SELECT foo FROM bar WHERE gazonk=:baz", ([":baz":"value"]));

    Binary values (BLOBs) may need to be placed in multisets.

  2. Arguments as you would use in sprintf. They are automatically quoted.

    res = query("select foo from bar where gazonk=%s","value");

Returns

Returns one of the following on success:

array(mapping(string:string))

The result as an array of mappings indexed on the name of the columns. The values are either strings with the display representations or zero for the SQL NULL value.

zero

The value 0 (zero) if the query didn't return any result (eg INSERT or similar).


Throws

Throws an exception if the query fails.

See also

typed_query , big_query , streaming_query


Method typed_query

array(mapping(string:mixed)) typed_query(object|string q, mixed ... extraargs)

Description

Sends an SQL query synchronously to the underlying SQL-server and returns the results in typed mode.

For the arguments, please see the query() function.

Returns

Returns one of the following on success:

array(mapping(string:mixed))

The result as an array of mappings indexed on the name of the columns. The values have the appropriate native pike types where they fit the SQL data types - see the class doc for details on typed mode.

zero

The value 0 (zero) if the query didn't return any result (eg INSERT or similar).


Note

Typed mode is not supported by all sql databases. If not supported, an error is thrown.

See also

query , big_typed_query


Method big_query

int|object big_query(object|string q, mixed ... extraargs)

Description

Sends an SQL query synchronously to the underlying SQL-server and returns the results in untyped mode.

For the arguments, please see the query() function.

The result is returned as an Sql.sql_result object in untyped mode. This allows for having some more info about the result as well as processing the result in a streaming fashion, although the result itself wasn't obtained streamingly from the server. Returns 0 if the query didn't return any result (e.g. INSERT or similar).

Note

Despite the name, this function is not only useful for "big" queries. It typically has less overhead than query also for ones that return only a few rows.

See also

query , streaming_query


Method big_typed_query

int|object big_typed_query(object|string q, mixed ... extraargs)

Description

Sends an SQL query synchronously to the underlying SQL-server and returns the results in typed mode.

For the arguments, please see the query() function.

The result is returned as an Sql.sql_result object in typed mode. This allows for having some more info about the result as well as processing the result in a streaming fashion, although the result itself wasn't obtained streamingly from the server. Returns 0 if the query didn't return any result (e.g. INSERT or similar).

Note

Typed mode is not supported by all sql databases. If not supported, an error is thrown.

Note

Despite the name, this function is not only useful for "big" queries. It typically has less overhead than typed_query also for ones that return only a few rows.

See also

query , typed_query , big_query , streaming_query


Method streaming_query

int|object streaming_query(object|string q, mixed ... extraargs)

Description

Sends an SQL query synchronously to the underlying SQL-server and returns the results streaming in untyped mode.

For the arguments, please see the query() function.

The result is returned as a streaming Sql.sql_result object in untyped mode. This allows for having results larger than the available memory, and returning some more info about the result. Returns 0 if the query didn't return any result (e.g. INSERT or similar). For the other arguments, they are the same as for the query() function.

Note

Streaming operation is not supported by all sql databases. If not supported, this function will fall back to calling big_query() .

See also

big_query , streaming_typed_query


Method streaming_typed_query

int|object streaming_typed_query(object|string q, mixed ... extraargs)

Description

Sends an SQL query synchronously to the underlying SQL-server and returns the results streaming in typed mode.

For the arguments, please see the query() function.

The result is returned as a streaming Sql.sql_result object in typed mode. This allows for having results larger than the available memory, and returning some more info about the result. Returns 0 if the query didn't return any result (e.g. INSERT or similar).

Note

Neither streaming operation nor typed results are supported by all sql databases. If not supported, this function will fall back to calling big_typed_query() .

See also

streaming_query , big_typed_query


Method create_db

void create_db(string db)

Description

Create a new database.

Parameter db

Name of database to create.


Method drop_db

void drop_db(string db)

Description

Drop database

Parameter db

Name of database to drop.


Method shutdown

void shutdown()

Description

Shutdown a database server.


Method reload

void reload()

Description

Reload the tables.


Method server_info

string server_info()

Description

Return info about the current SQL-server.


Method host_info

string host_info()

Description

Return info about the connection to the SQL-server.


Method list_dbs

array(string) list_dbs(string|void wild)

Description

List available databases on this SQL-server.

Parameter wild

Optional wildcard to match against.


Method list_tables

array(string) list_tables(string|void wild)

Description

List tables available in the current database.

Parameter wild

Optional wildcard to match against.


Method list_fields

array(mapping(string:mixed)) list_fields(string table, string|void wild)

Description

List fields available in the specified table

Parameter table

Table to list the fields of.

Parameter wild

Optional wildcard to match against.

  CLASS Sql.Sql.ZeroWrapper

Description

Wrapper to handle zero.

See also

zero


Method _sprintf

string _sprintf(int fmt, mapping(string:mixed) params)

Returns

Returns the following:

"NULL"

If fmt is 's'.

"ZeroWrapper()"

If fmt is 'O'.


Otherwise it formats a 0 (zero).

  CLASS Sql.mysql

Description

This class encapsulates a connection to a MySQL server, and implements the glue needed to access the Mysql module from the generic SQL module.

Typed mode

When query results are returned in typed mode, the MySQL data types are represented like this:

The NULL value

Returned as Val.null .

BIT, TINYINT, BOOL, SMALLINT, MEDIUMINT, INT, BIGINT

Returned as pike integers.

FLOAT, DOUBLE

Returned as pike floats.

DECIMAL

Returned as pike integers for fields that are declared to contain zero decimals, otherwise returned as Gmp.mpq objects.

DATE, DATETIME, TIME, YEAR

Returned as strings in their display representation (see the MySQL manual).

Calendar objects are not used partly because they always represent a specific point or range in time, which these MySQL types do not.

TIMESTAMP

Also returned as strings in the display representation.

The reason is that it's both more efficient and more robust (wrt time zone interpretations) to convert these to unix timestamps on the MySQL side rather than in the client glue. I.e. use the UNIX_TIMESTAMP function in the queries to retrieve them as unix timestamps on integer form.

String types

All string types are returned as pike strings. The MySQL glue can handle charset conversions for text strings - see set_charset and set_unicode_decode_mode .


Inherit mysql

inherit Mysql.mysql : mysql


Method set_unicode_encode_mode

int(0..1) set_unicode_encode_mode(int enable)

Description

Enables or disables unicode encode mode.

In this mode, if the server supports UTF-8 and the connection charset is latin1 (the default) or unicode then big_query handles wide unicode queries. Enabled by default.

Unicode encode mode works as follows: Eight bit strings are sent as latin1 and wide strings are sent using utf8. big_query sends SET character_set_client statements as necessary to update the charset on the server side. If the server doesn't support that then it fails, but the wide string query would fail anyway.

To make this transparent, string literals with introducers (e.g. _binary 'foo') are excluded from the UTF-8 encoding. This means that big_query needs to do some superficial parsing of the query when it is a wide string.

Returns
1

Unicode encode mode is enabled.

0

Unicode encode mode couldn't be enabled because an incompatible connection charset is set. You need to do set_charset ("latin1") or set_charset ("unicode") to enable it.


Note

Note that this mode doesn't affect the MySQL system variable character_set_connection, i.e. it will still be set to latin1 by default which means server functions like UPPER() won't handle non-latin1 characters correctly in all cases.

To fix that, do set_charset ("unicode"). That will allow unicode encode mode to work while utf8 is fully enabled at the server side.

Tip: If you enable utf8 on the server side, you need to send raw binary strings as _binary'...'. Otherwise they will get UTF-8 encoded by the server.

Note

When unicode encode mode is enabled and the connection charset is latin1, the charset accepted by big_query is not quite Unicode since latin1 is based on cp1252. The differences are in the range 0x80..0x9f where Unicode has control chars.

This small discrepancy is not present when the connection charset is unicode.

See also

set_unicode_decode_mode , set_charset


Method get_unicode_encode_mode

int get_unicode_encode_mode()

Description

Returns nonzero if unicode encode mode is enabled, zero otherwise.

See also

set_unicode_encode_mode


Method set_unicode_decode_mode

void set_unicode_decode_mode(int enable)

Description

Enable or disable unicode decode mode.

In this mode, if the server supports UTF-8 then non-binary text strings in results are automatically decoded to (possibly wide) unicode strings. Not enabled by default.

The statement "SET character_set_results = utf8" is sent to the server to enable the mode. When the mode is disabled, "SET character_set_results = xxx" is sent, where xxx is the connection charset that get_charset returns.

Parameter enable

Nonzero enables this feature, zero disables it.

Throws

Throws an exception if the server doesn't support this, i.e. if the statement above fails. The MySQL system variable character_set_results was added in MySQL 4.1.1.

An error is also thrown if Pike has been compiled with a MySQL client library older than 4.1.0, which lack the necessary support for this.

See also

set_unicode_encode_mode


Method get_unicode_decode_mode

int get_unicode_decode_mode()

Description

Returns nonzero if unicode decode mode is enabled, zero otherwise.

See also

set_unicode_decode_mode


Method set_charset

void set_charset(string charset)

Description

Changes the connection charset. Works similar to sending the query SET NAMES charset  but also records the charset on the client side so that various client functions work correctly.

charset is a MySQL charset name or the special value "unicode" (see below). You can use SHOW CHARACTER  SET to get a list of valid charsets.

Specifying "unicode" as charset is the same as "utf8" except that unicode encode and decode modes are enabled too. Briefly, this means that you can send queries as unencoded unicode strings and will get back non-binary text results as unencoded unicode strings. See set_unicode_encode_mode and set_unicode_decode_mode for further details.

Throws

Throws an exception if the server doesn't support this, i.e. if the statement SET NAMES fails. Support for it was added in MySQL 4.1.0.

Note

If charset is "latin1" and unicode encode mode is enabled (the default) then big_query can send wide unicode queries transparently if the server supports UTF-8. See set_unicode_encode_mode .

Note

If unicode decode mode is already enabled (see set_unicode_decode_mode ) then this function won't affect the result charset (i.e. the MySQL system variable character_set_results).

Actually, a query SET character_set_results = utf8 will be sent immediately after setting the charset as above if unicode decode mode is enabled and charset isn't "utf8".

Note

You should always use either this function or the "mysql_charset_name" option to create to set the connection charset, or more specifically the charset that the server expects queries to have (i.e. the MySQL system variable character_set_client). Otherwise big_query might not work correctly.

Afterwards you may change the system variable character_set_connection, and also character_set_results if unicode decode mode isn't enabled.

Note

The MySQL latin1 charset is close to Windows cp1252. The difference from ISO-8859-1 is a bunch of printable chars in the range 0x80..0x9f (which contains control chars in ISO-8859-1). For instance, the euro currency sign is 0x80.

You can use the mysql-latin1 encoding in the Locale.Charset module to do conversions, or just use the special "unicode" charset instead.

See also

get_charset , set_unicode_encode_mode , set_unicode_decode_mode


Method get_charset

string get_charset()

Description

Returns the MySQL name for the current connection charset.

Returns "unicode" if unicode encode mode is enabled and UTF-8 is used on the server side (i.e. in character_set_connection).

Note

In servers with full charset support (i.e. MySQL 4.1.0 or later), this corresponds to the MySQL system variable character_set_client (with one exception - see next note) and thus controls the charset in which queries are sent. The charset used for text strings in results might be something else (and typically is if unicode decode mode is enabled; see set_unicode_decode_mode ).

Note

If the returned charset is latin1 or unicode and unicode encode mode is enabled (the default) then character_set_client in the server might be either latin1 or utf8, depending on the last sent query. See set_unicode_encode_mode for more info.

See also

set_charset


Method quote

string quote(string s)

Description

Quote a string so that it can safely be put in a query.

Parameter s

String to quote.


Method latin1_to_utf8

string latin1_to_utf8(string s)

Description

Converts a string in MySQL latin1 format to UTF-8.


Method utf8_encode_query

string utf8_encode_query(string q, function(string:string) encode_fn)

Description

Encodes the appropriate sections of the query with encode_fn . Everything except strings prefixed by an introducer (i.e. _something or N) is encoded.


Method encode_time

string encode_time(int time, void|int date)

Description

Converts a system time value to an appropriately formatted time spec for the database.

Parameter time

Time to encode.

Parameter date

If nonzero then time is taken as a "full" unix time spec (where the date part is ignored), otherwise it's converted as a seconds-since-midnight value.


Method encode_date

string encode_date(int time)

Description

Converts a system time value to an appropriately formatted date-only spec for the database.

Parameter time

Time to encode.


Method encode_datetime

string encode_datetime(int time)

Description

Converts a system time value to an appropriately formatted date and time spec for the database.

Parameter time

Time to encode.


Method decode_time

int decode_time(string timestr, void|int date)

Description

Converts a database time spec to a system time value.

Parameter timestr

Time spec to decode.

Parameter date

Take the date part from this system time value. If zero, a seconds-since-midnight value is returned.


Method decode_date

int decode_date(string datestr)

Description

Converts a database date-only spec to a system time value. Assumes 4-digit years.

Parameter datestr

Date spec to decode.


Method decode_datetime

int decode_datetime(string timestr)

Description

Converts a database date and time spec to a system time value. Can decode strings missing the time part.

Parameter datestr

Date and time spec to decode.


Method big_query

Mysql.mysql_result big_query(string query, mapping(string|int:mixed)|void bindings, void|string charset)

Description

Sends a query to the server.

Parameter query

The SQL query.

Parameter bindings

An optional bindings mapping. See Sql.query for details about this.

Parameter charset

An optional charset that will be used temporarily while sending query to the server. If necessary, a query

SET character_set_client=charset

is sent to the server first, then query is sent as-is, and then the connection charset is restored again (if necessary).

Primarily useful with charset set to "latin1" if unicode encode mode (see set_unicode_encode_mode ) is enabled (the default) and you have some large queries (typically blob inserts) where you want to avoid the query parsing overhead.

Returns

A Mysql.mysql_result object is returned if the query is of a kind that returns a result. Zero is returned otherwise.

The individual fields are returned as strings except for NULL, which is returned as UNDEFINED .

See also

Sql.big_query() , big_typed_query() , streaming_query()


Method streaming_query

Mysql.mysql_result streaming_query(string query, mapping(string|int:mixed)|void bindings, void|string charset)

Description

Makes a streaming SQL query.

This function sends the SQL query query to the Mysql-server. The result of the query is streamed through the returned Mysql.mysql_result object. Note that the involved database tables are locked until all the results has been read.

In all other respects, it behaves like big_query .

See also

big_query() , streaming_typed_query()


Method big_typed_query

Mysql.mysql_result big_typed_query(string query, mapping(string|int:mixed)|void bindings, void|string charset)

Description

Makes a typed SQL query.

This function sends the SQL query query to the Mysql-server.

The types of the result fields depend on the corresponding SQL types. They are mapped as follows:

Sql.Null

The NULL value is returned as Sql.NULL .

int

Integer values are returned as int values.

float

Floating point values are returned as float values.

string

All other SQL field types are returned as string values.


In all other respects, it behaves like big_query .

See also

big_query() , streaming_typed_query()


Method streaming_typed_query

Mysql.mysql_result streaming_typed_query(string query, mapping(string|int:mixed)|void bindings, void|string charset)

Description

Makes a streaming typed SQL query.

This function acts as the combination of streaming_query() and big_typed_query() .

See also

big_typed_query() , streaming_typed_query()


Method is_keyword

int(0..1) is_keyword(string name)

Description

Return 1 if the argument name is a mysql keyword that needs to be quoted in a query. The list is currently up-to-date with MySQL 5.1.

  CLASS Sql.tds

Description

The TDS SQL-protocol.

This protocol is used by Sybase and Microsoft's SQL-servers.

Example

Sql.Sql con = Sql.Sql("tds://user:pass@host/database");

See also

Sql.Sql()


Method tds_error

void tds_error(string msg, mixed ... args)

Description

Format and report an error.


Method insert_id

int insert_id()

Description

Fetch the identity of the last insert (if available).

This performs the query "SELECT @@identity AS insert_id".

Returns

Returns the identity of the last insert as an integer if available. Otherwise returns 0 (zero).


Method server_info

string server_info()

Description

Return a string describing the server.


Method error

string error()

Description

Return the last error (or possibly the last warning or informational message).


Method create

void Sql.tds(string|void server, string|void database, string|void user, string|void password, mapping|void options)

Description

Connect to a remote SQL server via the TDS protocol.

Parameter server

Server to connect to.

Parameter database

Database to connect to.

Parameter user

User to access as.

An explicit domain may be specified by preceeding the user name with the domain name and a '\\'.

Parameter password

Password to access with.

Usually accessed via Sql.Sql() .

See also

Sql.Sql()

  ENUM Sql.tds.Token

Description

Tokens that may occur in the answers from the server.

  ENUM Sql.tds.EnvType

Description

Environment types.

Used by TDS_ENV_CHANGE_TOKEN

  ENUM Sql.tds.FieldType

Description

Field types.

  CLASS Sql.tds.Connection

Description

A connection to a TDS server.


Variable socket

Stdio.File Sql.tds.Connection.socket

Description

The actual TCP connection.


Method send_packet

InPacket send_packet(Packet p, int flag, int|void last)

Description

Send a packet to the TDS server.

Note

May only be called when the connection is idle.

Returns

If last is true an InPacket with the result will be returned.

  CLASS Sql.tds.Connection.InPacket

Description

An incoming packet from the TDS server.

  CLASS Sql.tds.Connection.Packet

Description

An outgoing packet to the TDS server.

  CLASS Sql.tds.compile_query

Description

A compiled query.


Method create

void Sql.tds.compile_query(string query)

Description

Compile a query.

See also

big_query()

  CLASS Sql.tds.big_query

Description

A query result set.


Method fetch_row

int|array(string|int) fetch_row()

Description

Fetch the next row from the result set.

Returns

Returns 0 (zero) if all rows have been returned.

Otherwise returns an array(string|int) with one entry for each field. If the field is NULL the entry will be 0 (zero), otherwise the entry will contain a string representing the value.


Method fetch_fields

array(mapping(string:mixed)) fetch_fields()

Description

Fetch a description of the fields in the result.

Returns

Returns an array with a mapping for each of the fields in the result.

The mappings contain the following information:

  • Standard fields:

    "name" : string

    The name of the field.

    "table" : string|void

    The name of the table (if available).


  • TDS-specific fields:

    "nullable" : int(0..1)

    1 if the field may contain NULL.

    "writeable" : int(0..1)

    1 if the field may be changed.

    "identity" : int(0..1)

    1 if the field is the identity for the row.

    "column_size" : int

    Width of the field.

    "timestamp" : int(0..1)

    Time stamp information for last change is available.

    "column_prec" : int|void

    Precision of the field.

    "column_scale" : int|void

    Scale exponent of the field.

    "usertype" : int

    Internal use only.

    "flags" : int
    "column_type" : int
    "cardinal_type" : int
    "varint_size" : int


Method create

void Sql.tds.big_query(string|compile_query query)

Description

Execute a query against the database.

Parameter query

The query to execute. This can either be a string, or a compiled query.

See also

compile_query()

  CLASS Sql.postgres

Description

This is an interface to the Postgres (Postgres95, pgsql) database server. This module may or may not be available on your Pike, depending whether the appropriate include and library files could be found at compile-time. Note that you do not need to have a Postgres server running on your host to use this module: you can connect to the database over a TCP/IP socket.

Note

This driver has been deprecated. You should use the more advanced driver Sql.pgsql to access PostgreSQL databases instead.

Note

Also note that this module uses blocking I/O to connect to the server. It is thread-safe, and so it can be used in a multithread environment.

The behavior of the Postgres C API also depends on certain environment variables defined in the environment of the Pike interpreter; some notice and warning notifications might are dumped on stderr.

"PGHOST"

Sets the name of the default host to connect to. It defaults to "localhost".

"PGOPTIONS"

Sets some extra flags for the frontend-backend connection. do not set unless you're sure of what you're doing.

"PGPORT"

Sets the default port to connect to, otherwise it will use compile-time defaults (that is: the time you compiled the postgres library, not the Pike driver).

"PGTTY"

Sets the file to be used for Postgres frontend debugging. Do not use, unless you're sure of what you're doing.

"PGDATABASE"

Sets the default database to connect to.

"PGREALM"

Sets the default realm for Kerberos authentication. I never used this, so I can't help you.


Refer to the Postgres documentation for further details.

See also

Sql.pgsql , Sql.Sql , Postgres.postgres , Sql.postgres_result


Inherit mo

inherit Postgres.postgres : mo


Method select_db

void select_db(string dbname)

Description

This function allows you to connect to a database. Due to restrictions of the Postgres frontend-backend protocol, you always have to be connected to a database, so in fact this function just allows you to connect to a different database on the same server.

Note

This function can raise exceptions if something goes wrong (backend process not running, not enough permissions..)

See also

create


Method error

string error()

Description

This function returns the textual description of the last server-related error. Returns 0 if no error has occurred yet. It is not cleared upon reading (can be invoked multiple times, will return the same result until a new error occurs).

See also

big_query


Method host_info

string host_info()

Description

This function returns a string describing what host are we talking to, and how (TCP/IP or UNIX sockets).


Method reset

void reset()

Description

This function resets the connection to the backend. Can be used for a variety of reasons, for example to detect the status of a connection.

Note

This function is Postgres-specific, and thus it is not available through the generic SQL-interface.


Variable version

string Sql.postgres.version

Description

Should you need to report a bug to the author, please submit along with the report the driver version number, as returned by this call.


Method create

void Sql.postgres()
void Sql.postgres(string host, void|string database, void|string user, void|string password, void|mapping options)

Description

With no arguments, this function initializes (reinitializes if a connection had been previously set up) a connection to the Postgres backend. Since Postgres requires a database to be selected, it will try to connect to the default database. The connection may fail however for a variety of reasons, in this case the most likely of all is because you don't have enough authority to connect to that database. So use of this particular syntax is discouraged.

The host argument can have the syntax "hostname" or "hostname:portname". This allows to specify the TCP/IP port to connect to. If it is 0 or "", it will try to connect to localhost, default port.

The database argument specifies the database to connect to. If 0 or "", it will try to connect to the specified database.

The username and password arguments are silently ignored, since the Postgres C API doesn't allow to connect to the server as any user different than the user running the interface.

Note

You need to have a database selected before using the sql-object, otherwise you'll get exceptions when you try to query it. Also notice that this function can raise exceptions if the db server doesn't respond, if the database doesn't exist or is not accessible by you.

You don't need bothering about syncronizing the connection to the database: it is automatically closed (and the database is sync-ed) when the object is destroyed.

See also

Sql.pgsql , Postgres.postgres , Sql.Sql , postgres->select_db


Method set_notify_callback

void set_notify_callback()
void set_notify_callback(function f)
void set_notify_callback(function f, int|float poll_delay)

Description

With Postgres you can associate events and notifications to tables. This function allows you to detect and handle such events.

With no arguments, resets and removes any callback you might have put previously, and any polling cycle.

With one argument, sets the notification callback (there can be only one for each sqlobject).

With two arguments, sets a notification callback and sets a polling cycle.

The polling cycle is necessary because of the way notifications are delivered, that is piggyback with a query result. This means that if you don't do any query, you'll receive no notification. The polling cycle starts a call_out cycle which will do an empty query when the specified interval expires, so that pending notifications may be delivered.

The callback function must return no value, and takes a string argument, which will be the name of the table on which the notification event has occurred. In future versions, support for user-specified arguments will be added.

Note

The polling cycle can be run only if your process is in "event-driven mode" (that is, if 'main' has returned a negative number).

This function is Postgres-specific, and thus it is not available through the generic SQL-interface.

FIXME

An integer can be passed as first argument, but it's effect is not documented.


Method create_db

void create_db(string db)

Description

This function creates a new database with the given name (assuming we have enough permissions to do this).

See also

drop_db


Method drop_db

void drop_db(string db)

Description

This function destroys a database and all the data it contains (assuming we have enough permissions to do so).

See also

create_db


Method server_info

string server_info()

Description

This function returns a string describing the server we are talking to. It has the form "servername/serverversion" (like the HTTP protocol description) and is most useful in conjunction with the generic SQL-server module.


Method list_dbs

array(string) list_dbs(void|string glob)

Description

Lists all the databases available on the server. If glob is specified, lists only those databases matching it.


Method list_tables

array(string) list_tables(void|string glob)

Description

Returns an array containing the names of all the tables in the currently selected database. If a glob is specified, it will return only those tables whose name matches it.


Method list_fields

array(mapping(string:mixed)) list_fields(string table, void|string wild)

Description

Returns a mapping, indexed on the column name, of mappings describing the attributes of a table of the current database. If a glob is specified, will return descriptions only of the columns matching it.

The currently defined fields are:

"has_rules" : int 
"is_shared" : int 
"owner" : string

The textual representation of a Postgres uid.

"length" : string 
"text" : string

A textual description of the internal (to the server) type-name

"default" : mixed 
"expires" : string

The "relexpires" attribute for the table. Obsolescent; modern versions of Postgres don't seem to use this feature, so don't count on this field to contain any useful value.



Method big_query

int|object big_query(object|string q, mapping(string|int:mixed)|void bindings)

Description

This is the only provided interface which allows you to query the database. If you wish to use the simpler "query" function, you need to use the Sql.Sql generic SQL-object.

It returns a postgres_result object (which conforms to the Sql.sql_result standard interface for accessing data). I recommend using query() for simpler queries (because it is easier to handle, but stores all the result in memory), and big_query() for queries you expect to return huge amounts of data (it's harder to handle, but fetches results on demand).

Note

This function can raise exceptions.

See also

Sql.Sql , Sql.sql_result


Method streaming_query

int|object streaming_query(object|string q, mapping(string|int:mixed)|void bindings)

Description

This is an alias for big_query() , since big_query() already supports streaming.

See also

big_query , Sql.Sql , Sql.sql_result


Inherit pgsql

inherit Sql.pgsql : pgsql

Description

Maps SQL-urls for postgres://[user[:password]@][hostname][:port][/database] onto pgsql://[user[:password]@][hostname][:port][/database]

The reason this happens, is because Pike was compiled without libpq support, therefore Pike falls back to the faster, smaller memory footprint, more advanced and native PostgreSQL driver called Sql.pgsql .

See also

Sql.pgsql , Sql.Sql

  CLASS Sql.pgsqls

Description

Implements SQL-urls for pgsqls://[user[:password]@][hostname][:port][/database]

Sets the connection to SSL-mode, otherwise identical to Sql.pgsql .

See also

Sql.pgsql , Sql.Sql


Inherit pgsql

inherit Sql.pgsql : pgsql

  CLASS Sql.pgsql

Description

This is an interface to the PostgreSQL database server. This module is independent of any external libraries. Note that you do not need to have a PostgreSQL server running on your host to use this module: you can connect to the database over a TCP/IP socket.

This module replaces the functionality of the older Sql.postgres and Postgres.postgres modules.

This module supports the following features:

  • PostgreSQL network protocol version 3, authentication methods currently supported are: cleartext and MD5 (recommended).

  • Streaming queries which do not buffer the whole resultset in memory.

  • Automatic binary transfers to and from the database for most common datatypes (amongst others: integer, text and bytea types).

  • Automatic character set conversion and native wide string support. Supports UTF8/Unicode for multibyte characters, and all single-byte character sets supported by the database.

  • SQL-injection protection by allowing just one statement per query and ignoring anything after the first (unquoted) semicolon in the query.

  • COPY support for streaming up- and download.

  • Accurate error messages.

  • Automatic precompilation of complex queries (session cache).

  • Multiple simultaneous queries on the same database connection.

  • Cancelling of long running queries by force or by timeout.

  • Event driven NOTIFY.

  • SSL encrypted connections (optional or forced).

Check the PostgreSQL documentation for further details.

Note

Multiple simultaneous queries on the same database connection is a feature that none of the other database drivers for Pike support. So, although it's efficient, its use will make switching database drivers difficult.

See also

Sql.Sql , Sql.postgres , http://www.postgresql.org/docs/


Method create

void Sql.pgsql()
void Sql.pgsql(string host, void|string database, void|string user, void|string password, void|mapping(string:mixed) options)

Description

With no arguments, this function initialises (reinitialises if a connection has been set up previously) a connection to the PostgreSQL backend. Since PostgreSQL requires a database to be selected, it will try to connect to the default database. The connection may fail however, for a variety of reasons; in this case the most likely reason is because you don't have sufficient privileges to connect to that database. So use of this particular syntax is discouraged.

Parameter host

Should either contain "hostname" or "hostname:portname". This allows you to specify the TCP/IP port to connect to. If the parameter is 0 or "", it will try to connect to localhost, default port.

Parameter database

Specifies the database to connect to. Not specifying this is only supported if the PostgreSQL backend has a default database configured. If you do not want to connect to any live database, you can use template1 .

Parameter options

Currently supports at least the following:

"reconnect" : int

Set it to zero to disable automatic reconnects upon losing the connection to the database. Not setting it, or setting it to one, will cause one timed reconnect to take place. Setting it to -1 will cause the system to try and reconnect indefinitely.

"use_ssl" : int

If the database supports and allows SSL connections, the session will be SSL encrypted, if not, the connection will fallback to plain unencrypted.

"force_ssl" : int

If the database supports and allows SSL connections, the session will be SSL encrypted, if not, the connection will abort.

"text_query" : int

Send queries to and retrieve results from the database using text instead of the, generally more efficient, default native binary method. Turning this on will allow multiple statements per query separated by semicolons.

"cache_autoprepared_statements" : int

If set to zero, it disables the automatic statement prepare and cache logic; caching prepared statements can be problematic when stored procedures and tables are redefined which leave stale references in the already cached prepared statements.

"client_encoding" : string

Character encoding for the client side, it defaults to using the default encoding specified by the database, e.g. UTF8 or SQL_ASCII .

"standard_conforming_strings" : string

When on, backslashes in strings must not be escaped any longer, quote() automatically adjusts quoting strategy accordingly.

"escape_string_warning" : string

When on, a warning is issued if a backslash (\) appears in an ordinary string literal and standard_conforming_strings is off, defaults to on


For the numerous other options please check the PostgreSQL manual.

Note

You need to have a database selected before using the sql-object, otherwise you'll get exceptions when you try to query it. Also notice that this function can raise exceptions if the db server doesn't respond, if the database doesn't exist or is not accessible by you.

See also

Postgres.postgres , Sql.Sql , select_db() , http://www.postgresql.org/search/?u=%2Fdocs%2Fcurrent%2F&q=client+connection+defaults


Method error

string error(void|int clear)

Returns

The textual description of the last server-related error. Returns 0 if no error has occurred yet. It is not cleared upon reading (can be invoked multiple times, will return the same result until a new error occurs).

During the execution of a statement, this function accumulates all non-error messages (notices, warnings, etc.). If a statement does not generate any errors, this function will return all collected messages from the last statement.

Note

The string returned is not newline-terminated.

Parameter clear

To clear the error, set it to 1.

See also

big_query()


Method host_info

string host_info()

Description

This function returns a string describing what host are we talking to, and how (TCP/IP or UNIX sockets).

See also

server_info()


Method is_open

int is_open()

Description

Returns true if the connection seems to be open.

Note

This function only checks that there's an open connection, and that the other end hasn't closed it yet. No data is sent over the connection.

For a more reliable check of whether the connection is alive, please use ping() .

See also

ping()


Method ping

int ping()

Description

Check whether the connection is alive.

Returns

Returns one of the following:

0

Everything ok.

1

The connection reconnected automatically.

-1

The server has gone away, and the connection is dead.


See also

is_open()


Method cancelquery

void cancelquery()

Description

Cancels the currently running query.

See also

reload() , resync()

Note

This function is PostgreSQL-specific, and thus it is not available through the generic SQL-interface.


Method set_charset

void set_charset(string charset)

Description

Changes the connection charset. When set to UTF8 , the query, parameters and results can be Pike-native wide strings.

Parameter charset

A PostgreSQL charset name.

See also

get_charset() , create() , http://www.postgresql.org/search/?u=%2Fdocs%2Fcurrent%2F&q=character+sets


Method get_charset

string get_charset()

Returns

The PostgreSQL name for the current connection charset.

See also

set_charset() , getruntimeparameters() , http://www.postgresql.org/search/?u=%2Fdocs%2Fcurrent%2F&q=character+sets


Method getruntimeparameters

mapping(string:string) getruntimeparameters()

Returns

Currently active runtimeparameters for the open session; these are initialised by the options parameter during session creation, and then processed and returned by the server. Common values are:

"client_encoding" : string

Character encoding for the client side, e.g. UTF8 or SQL_ASCII .

"server_encoding" : string

Character encoding for the server side as determined when the database was created, e.g. "UTF8" or "SQL_ASCII".

"DateStyle" : string

Date parsing/display, e.g. "ISO, DMY".

"TimeZone" : string

Default timezone used by the database, e.g. "localtime".

"standard_conforming_strings" : string

When on, backslashes in strings must not be escaped any longer.

"session_authorization" : string

Displays the authorisationrole which the current session runs under.

"is_superuser" : string

Indicates if the current authorisationrole has database-superuser privileges.

"integer_datetimes" : string

Reports wether the database supports 64-bit-integer dates and times.

"server_version" : string

Shows the server version, e.g. "8.3.3".


The values can be changed during a session using SET commands to the database. For other runtimeparameters check the PostgreSQL documentation.

See also

http://www.postgresql.org/search/?u=%2Fdocs%2Fcurrent%2F&q=client+connection+defaults

Note

This function is PostgreSQL-specific, and thus it is not available through the generic SQL-interface.


Method getstatistics

mapping(string:mixed) getstatistics()

Returns

A set of statistics for the current session:

"warnings_dropped" : int

Number of warnings/notices generated by the database but not collected by the application by using error() after the statements that generated them.

"skipped_describe_count" : int

Number of times the driver skipped asking the database to describe the statement parameters because it was already cached.

"used_prepared_statements" : int

Numer of times prepared statements were used from cache instead of reparsing in the current session.

"current_prepared_statements" : int

Cache size of currently prepared statements.

"current_prepared_statement_hits" : int

Sum of the number hits on statements in the current statement cache.

"prepared_portal_count" : int

Total number of prepared portals generated.

"prepared_statement_count" : int

Total number of prepared statements generated.

"portals_opened_count" : int

Total number of portals opened, i.e. number of statements issued to the database.

"blocked_count" : int

Number of times the driver had to (briefly) wait for the database to send additional data.

"bytes_received" : int

Total number of bytes received from the database so far.

"messages_received" : int

Total number of messages received from the database (one SQL-statement requires multiple messages to be exchanged).

"bytes_sent" : int

Total number of bytes sent to the database so far.

"packets_sent" : int

Total number of packets sent to the database (one packet usually contains multiple messages).

"reconnect_count" : int

Number of times the connection to the database has been lost.

"portals_in_flight" : int

Currently still open portals, i.e. running statements.


Note

This function is PostgreSQL-specific, and thus it is not available through the generic SQL-interface.


Method setcachedepth

int setcachedepth(void|int newdepth)

Parameter newdepth

Sets the new cachedepth for automatic caching of prepared statements.

Returns

The previous cachedepth.

Note

This function is PostgreSQL-specific, and thus it is not available through the generic SQL-interface.


Method settimeout

int settimeout(void|int newtimeout)

Parameter newtimeout

Sets the new timeout for long running queries.

Returns

The previous timeout.

Note

This function is PostgreSQL-specific, and thus it is not available through the generic SQL-interface.


Method setportalbuffersize

int setportalbuffersize(void|int newportalbuffersize)

Parameter newportalbuffersize

Sets the new portalbuffersize for buffering partially concurrent queries.

Returns

The previous portalbuffersize.

Note

This function is PostgreSQL-specific, and thus it is not available through the generic SQL-interface.


Method setfetchlimit

int setfetchlimit(void|int newfetchlimit)

Parameter newfetchlimit

Sets the new fetchlimit to interleave queries.

Returns

The previous fetchlimit.

Note

This function is PostgreSQL-specific, and thus it is not available through the generic SQL-interface.


Method close

void close()

Description

Closes the connection to the database, any running queries are terminated instantly.

Note

This function is PostgreSQL-specific, and thus it is not available through the generic SQL-interface.


Method reload

void reload()

Description

For PostgreSQL this function performs the same function as resync() .

See also

resync() , cancelquery()


Method resync

void resync()

Description

Resyncs the database session; typically used to make sure the session is not still in a dangling transaction.

If called while queries/portals are still in-flight, this function is a no-op.

If called while the connection is in idle state, the function is lightweight and briefly touches base with the database server to make sure client and server are in sync.

If issued while inside a transaction, it will rollback the transaction, close all open cursors, drop all temporary tables and reset all session variables to their default values.

See also

cancelquery() , reload()

Note

This function is PostgreSQL-specific, and thus it is not available through the generic SQL-interface.


Method select_db

void select_db(string dbname)

Description

This function allows you to connect to a database. Due to restrictions of the Postgres frontend-backend protocol, you always have to be connected to a database, so in fact this function just allows you to connect to a different database on the same server.

Note

This function can raise exceptions if something goes wrong (backend process not running, insufficient privileges...)

See also

create()


Method set_notify_callback

void set_notify_callback(string condition, void|function(int:void) notify_cb, void|int selfnotify, mixed ... args)

Description

With PostgreSQL you can LISTEN to NOTIFY events. This function allows you to detect and handle such events.

Parameter condition

Name of the notification event we're listening to. A special case is the empty string, which matches all events, and can be used as fallback function which is called only when the specific condition is not handled. Another special case is _reconnect which gets called whenever the connection unexpectedly drops and reconnects to the database.

Parameter notify_cb

Function to be called on receiving a notification-event of condition condition . The callback function is invoked with void notify_cb(pid,condition,extrainfo, .. args); pid is the process id of the database session that originated the event. condition contains the current condition. extrainfo contains optional extra information specified by the database. The rest of the arguments to notify_cb are passed verbatim from args . The callback function must return no value.

Parameter selfnotify

Normally notify events generated by your own session are ignored. If you want to receive those as well, set selfnotify to one.

Parameter args

Extra arguments to pass to notify_cb .

Note

This function is PostgreSQL-specific, and thus it is not available through the generic SQL-interface.


Method quote

string quote(string s)

Returns

The given string, but escapes/quotes all contained magic characters according to the quoting rules of the current session for non-binary arguments in textual SQL-queries.

Note

Quoting must not be done for parameters passed in bindings.

See also

big_query() , quotebinary() , create()


Method quotebinary

string quotebinary(string s)

Returns

The given string, but escapes/quotes all contained magic characters for binary (bytea) arguments in textual SQL-queries.

Note

Quoting must not be done for parameters passed in bindings.

See also

big_query() , quote()

Note

This function is PostgreSQL-specific, and thus it is not available through the generic SQL-interface.


Method create_db

void create_db(string db)

Description

This function creates a new database (assuming we have sufficient privileges to do this).

Parameter db

Name of the new database.

See also

drop_db()


Method drop_db

void drop_db(string db)

Description

This function destroys a database and all the data it contains (assuming we have sufficient privileges to do so). It is not possible to delete the database you're currently connected to. You can connect to database template1 to avoid connecting to any live database.

Parameter db

Name of the database to be deleted.

See also

create_db()


Method server_info

string server_info()

Returns

A string describing the server we are talking to. It has the form "servername/serverversion" (like the HTTP protocol description) and is most useful in conjunction with the generic SQL-server module.

See also

host_info()


Method list_dbs

array(string) list_dbs(void|string glob)

Returns

An array of the databases available on the server.

Parameter glob

If specified, list only those databases matching it.


Method list_tables

array(string) list_tables(void|string glob)

Returns

An array containing the names of all the tables and views in the path in the currently selected database.

Parameter glob

If specified, list only the tables with matching names.


Method list_fields

array(mapping(string:mixed)) list_fields(void|string table, void|string glob)

Returns

A mapping, indexed on the column name, of mappings describing the attributes of a table of the current database. The currently defined fields are:

"schema" : string

Schema the table belongs to

"table" : string

Name of the table

"kind" : string

Type of table

"owner" : string

Tableowner

"rowcount" : int

Estimated rowcount of the table

"datasize" : int

Estimated total datasize of the table in bytes

"indexsize" : int

Estimated total indexsize of the table in bytes

"name" : string

Name of the column

"type" : string

A textual description of the internal (to the server) column type-name

"typeoid" : int

The OID of the internal (to the server) column type

"length" : string

Size of the columndatatype

"default" : mixed

Default value for the column

"is_shared" : int

If the table has any indices

"has_index" : int
"has_primarykey" : int

If the table has a primary key


Parameter glob

If specified, list only the tables with matching names. Setting it to * will include system columns in the list.


Method status_commit

string status_commit()

Returns

The current commitstatus of the connection. Returns either one of:

idle
intransaction
infailedtransaction

Note

This function is PostgreSQL-specific, and thus it is not available through the generic SQL-interface.


Method big_query

Sql.pgsql_util.pgsql_result big_query(string query)
Sql.pgsql_util.pgsql_result big_query(string query, mapping bindings)

Description

This is the only provided interface which allows you to query the database. If you wish to use the simpler Sql.Sql()->query() function, you need to use the Sql.Sql generic SQL-object.

Bindings are supported natively straight across the network. Special bindings supported are:

":_cache" : int

Forces caching on or off for the query at hand.

":_text" : int

Forces text mode in communication with the database for queries on or off for the query at hand. Potentially more efficient than the default binary method for simple queries with small or no result sets. Note that this mode causes all but the first query result of a list of semicolon separated statements to be discarded.


Returns

A Sql.pgsql_util.pgsql_result object (which conforms to the Sql.sql_result standard interface for accessing data). It is recommended to use Sql.Sql()->query() for simpler queries (because it is easier to handle, but stores all the result in memory), and Sql.Sql()->big_query() for queries you expect to return huge amounts of data (it's harder to handle, but fetches results on demand).

Note

This function can raise exceptions.

Note

This function supports multiple simultaneous queries (portals) on a single database connection. This is a feature not commonly supported by other database backends.

Note

This function, by default, does not support multiple queries in one querystring. I.e. it allows for but does not require a trailing semicolon, but it simply ignores any commands after the first unquoted semicolon. This can be viewed as a limited protection against SQL-injection attacks. To make it support multiple queries in one querystring, use the :_text option.

See also

big_typed_query() , Sql.Sql , Sql.sql_result , Sql.Sql()->query() , Sql.pgsql_util.pgsql_result


Method streaming_query

object streaming_query(string q, void|mapping(string|int:mixed) bindings)

Description

This is an alias for big_query() , since big_query() already supports streaming of multiple simultaneous queries through the same connection.

See also

big_query() , big_typed_query() , Sql.Sql , Sql.sql_result


Method big_typed_query

object big_typed_query(string q, void|mapping(string|int:mixed) bindings)

Description

This function returns an object that allows streaming and typed results.

See also

big_query() , Sql.Sql , Sql.sql_result

  CLASS Sql.null

Description

The NULL Sql handler.

This is an empty Sql handler typically used to test other functionality of the Sql module.


Method quote

string quote(string s)

Returns

sprintf ("quote(%q)", s).


Method query

array(mapping(string:mixed)) query(string query, mapping(string:mixed)|void bindings)

Returns

Returns an array with a single element:

"query" : string

The query string before formating.

"bindings" : string

sprintf ("%O", bindings ).

"formatted_query" : string

The formatted query.


  CLASS Sql.postgres_result

Description

Sql.postgres_result contains the result of a Postgres-query. See Sql.postgres for a description of this program's functions.


Inherit postgres_result

inherit Postgres.postgres_result : postgres_result

  CLASS Sql.sqlite

Description

Low-level interface to SQLite3 databases.

This class should typically not be accessed directly, but instead via Sql.Sql() with the scheme "sqlite://".


Method insert_id

int insert_id()

Description

Returns the value of the ROWID (aka OID, aka _ROWID_, or declared INTEGER PRIMARY KEY) column for the most recent successful INSERT operation, or 0 (zero) if no INSERT operations have been performed on the connection yet.

  CLASS Sql.sqlite.ResObj

Description

Result object from big_query() .

  Module Sql.pgsql_util

Description

Some pgsql utility functions

  CLASS Sql.pgsql_util.pgsql_result

Description

The result object returned by Sql.pgsql()->big_query() , except for the noted differences it behaves the same as Sql.sql_result .

See also

Sql.sql_result , Sql.pgsql , Sql.Sql , Sql.pgsql()->big_query()


Method status_command_complete

string status_command_complete()

Description

Returns the command-complete status for this query.

See also

affected_rows()

Note

This function is PostgreSQL-specific, and thus it is not available through the generic SQL-interface.


Method affected_rows

int affected_rows()

Description

Returns the number of affected rows by this query.

See also

status_command_complete()

Note

This function is PostgreSQL-specific, and thus it is not available through the generic SQL-interface.


Method num_fields

int num_fields()

See also

Sql.sql_result()->num_fields()


Method num_rows

int num_rows()

See also

Sql.sql_result()->num_rows()


Method eof

int eof()

See also

Sql.sql_result()->eof()


Method fetch_fields

array(mapping(string:mixed)) fetch_fields()

See also

Sql.sql_result()->fetch_fields()


Method fetch_row

array(mixed) fetch_row()
void fetch_row(string|array(string) copydatasend)

Returns

One result row at a time.

When using COPY FROM STDOUT, this method returns one row at a time as a single string containing the entire row.

Parameter copydatasend

When using COPY FROM STDIN, this method accepts a string or an array of strings to be processed by the COPY command; when sending the amount of data sent per call does not have to hit row or column boundaries.

The COPY FROM STDIN sequence needs to be completed by either explicitly or implicitly destroying the result object, or by passing a zero argument to this method.

See also

eof()

  Module Sql.sql_util

Description

Some SQL utility functions


Method quote

string quote(string s)

Description

Quote a string so that it can safely be put in a query.

Parameter s

String to quote.


Method fallback

void fallback()

Description

Throw an error in case an unimplemented function is called.


Method emulate_bindings

string emulate_bindings(string query, mapping(string|int:mixed)|void bindings, void|object driver)

Description

Build a raw SQL query, given the cooked query and the variable bindings It's meant to be used as an emulation engine for those drivers not providing such a behaviour directly (i.e. Oracle). The raw query can contain some variables (identified by prefixing a colon to a name or a number (i.e. ":var" or ":2"). They will be replaced by the corresponding value in the mapping.

Parameter query

The query.

Parameter bindings

Optional mapping containing the variable bindings. Make sure that no confusion is possible in the query. If necessary, change the variables' names.

  CLASS Sql.sql_util.UnicodeWrapper

Description

Result object wrapper performing utf8 decoding of all fields.


syntax

protected object Sql.sql_util.UnicodeWrapper.master_resultvoid Sql.sql_util.UnicodeWrapper(object master_result)


Method num_rows

int num_rows()

Description

Returns the number of rows in the result.


Method num_fields

int num_fields()

Description

Returns the number of fields in the result.


Method eof

int(0..1) eof()

Description

Returns 1 if there are no more rows in the result.


Variable field_info

protected array(int|mapping(string:mixed)) Sql.sql_util.UnicodeWrapper.field_info

Description

Cached fetch_fields() result.


Method fetch_fields

array(int|mapping(string:mixed)) fetch_fields()

Description

Returns Information about the fields in the result.

The following fields are converted from UTF8 if present:

"name" : string

The name of the field. Always present.

"table" : string

The table the field is from. Not present from all databases.

"default" : string

The default value for the column. Not available from all databases.



Method seek

void seek(int rows)

Description

Skip ahead the specified number of rows.


Method fetch_row

int|array(string) fetch_row()

Description

Fetch the next row from the result.

All strings in the result are decoded from UTF8.


Method fetch_json_result

int|string fetch_json_result()

Description

JSON is always utf8 default, do nothing.

  CLASS Sql.sql_util.MySQLUnicodeWrapper

Description

Result wrapper for MySQL that performs UTF-8 decoding of all nonbinary fields. Useful if the result charset of the connection has been set to UTF-8.

Note

There's normally no need to use this class directly. It's used automatically when Mysql.set_unicode_decode_mode is activated.


Inherit UnicodeWrapper

inherit UnicodeWrapper : UnicodeWrapper

  Module Mysql

Description

This module enables access to the Mysql database from within Pike. Use Sql.Sql for general database access.

Mysql is available from http://www.mysql.com.

See also

Mysql.mysql , Mysql.mysql_result , Sql.Sql

  CLASS Mysql.mysql_result

Description

Objects of this class contain the result from Mysql queries.

See also

Mysql.mysql , Mysql.mysql->big_query()


Method create

void Mysql.mysql_result(Mysql.mysql connection)

Description

Make a new Mysql.mysql_result object.

See also

Mysql.mysql->big_query() , Mysql.mysql->list_dbs() , Mysql.mysql->list_tables() , Mysql.mysql->list_processes() , Mysql.mysql


Method num_rows

int num_rows()

Description

Number of rows in the result.

See also

num_fields()


Method num_fields

int num_fields()

Description

Number of fields in the result.

See also

num_rows()


Method field_seek

void field_seek(int field_no)

Description

Skip to specified field.

Places the field cursor at the specified position. This affects which field mysql_result->fetch_field() will return next.

Fields are numbered starting with 0.

Note

This function is usually not enabled. To enable it SUPPORT_FIELD_SEEK must be defined when compiling the mysql-module.

See also

fetch_field() , fetch_fields()


Method eof

int(0..1) eof()

Description

Sense end of result table.

Returns 1 when all rows have been read, and 0 (zero) otherwise.

See also

fetch_row()


Method fetch_field

int|mapping(string:mixed) fetch_field()

Description

Return specification of the current field.

Returns a mapping with information about the current field, and advances the field cursor one step. Returns 0 (zero) if there are no more fields.

The mapping contains the same entries as those returned by Mysql.mysql->list_fields() , except that the entry "default" is missing.

Note

This function is usually not enabled. To enable it SUPPORT_FIELD_SEEK must be defined when compiling the mysql-module.

See also

fetch_fields() , field_seek() , Mysql.mysql->list_fields()


Method fetch_fields

array(int|mapping(string:mixed)) fetch_fields()

Description

Get specification of all remaining fields.

Returns an array with one mapping for every remaining field in the result table.

The returned data is similar to the data returned by Mysql.mysql->list_fields() , except for that the entry "default" is missing.

Note

Resets the field cursor to 0 (zero).

This function always exists even when fetch_field() and field_seek() don't.

See also

fetch_field() , field_seek() , Mysql.mysql->list_fields()


Method seek

void seek(int rows)

Description

Skip ahead rows rows.

Note

Can only seek forward.

See also

fetch_row()


Method fetch_row

int|array(string) fetch_row()

Description

Fetch the next row from the result.

Returns an array with the contents of the next row in the result. Advances the row cursor to the next now.

Returns 0 (zero) at the end of the table.

See also

seek()


Method fetch_json_result

string fetch_json_result()

Description

Fetch all remaining rows and return them as JSON-encoded data.

See also

fetch_row()

FIXME

Ensure that all fields (including binary fields) are UTF-8 encoded.

  CLASS Mysql.mysql

Description

Interface to the Mysql database.

This class enables access to the Mysql database from within Pike.

Mysql is available from http://www.mysql.com.

See also

Mysql.mysql_result , Sql.Sql


Method create

void Mysql.mysql()
void Mysql.mysql(string host)
void Mysql.mysql(string host, string database)
void Mysql.mysql(string host, string database, string user)
void Mysql.mysql(string host, string database, string user, string password)
void Mysql.mysql(string host, string database, string user, string password, mapping(string:string|int) options)

Description

Connect to a Mysql database.

To access the Mysql database, you must first connect to it. This is done with this function.

Parameter host

If you give no argument, or give "" as host it will connect with a UNIX-domain socket, which can be a big performance gain.

Parameter options

This optional mapping can contain zero or more of the following parameters:

"init_command" : string

Command to execute on connect.

"timeout" : int

Timeout in seconds.

"compress" : int(0..1)

Enable compressed protocol.

"mysql_config_file" : string

Change config file from "my.cnf".

"mysql_group" : string

Specify additional group to read from config file.

"mysql_named_pipe" : int(0..1)

Use named pipe to connect to server.

"mysql_local_infile" : int(0..1)

Enable use of LOCAL INFILE (security).

"mysql_charset_dir" : string

Change charset directory.

"mysql_charset_name" : string

Set connection charset - see set_charset for details. The default is "latin1". As opposed to set_charset , this way of specifying the connection charset doesn't require MySQL 4.1.0.

"unicode_decode_mode" : int

Enable unicode decode mode for the connection if nonzero. In this mode non-binary string results are automatically converted to (possibly wide) unicode strings. An error is thrown if the server doesn't support this. See set_unicode_decode_mode .

"ssl_key" : string

Path to SSL-key for use in SSL-communication.

"ssl_cert" : string

Path to SSL-cert for use in SSL-communication.

"ssl_ca" : string

Path to SSL-CA for use in SSL-communication.

"ssl_capath" : string

Path to SSL-CAPATH for use in SSL-communication.

"ssl_cipher" : string

FIXME

"connect_options" : int

Options used when connecting to the server. See mysql documentation for more information.


Note

Some options may not be implemented. Unimplemented options are silently ignored.

Note

To use SSL-connections, set the SSL-parameters correctly. They correspond to the parameters given to the mysql-client with the same name so make sure that the mysql-client works with SSL and set these parameters to the same values and everything should work. If SSL-options are loaded from a config-file, one may set the connect_options to include CLIENT_SSL.

Note

If Pike has been built with an old MySQL client lib then it might not be possible to specify some charsets that the server supports with the "mysql_charset_name" option. In such cases it's possible that set_charset works better (provided the server is 4.1 or newer).


Method _sprintf

string _sprintf(int type, void|mapping flags)


Method is_open

int is_open()

Description

Returns true if the connection seems to be open.

Note

This function only checks that there's an open connection, and that the other end hasn't closed it yet. No data is sent over the connection.

For a more reliable check of whether the connection is alive, please use ping() .

See also

ping()


Method ping

int ping()

Description

Check whether the connection is alive.

Returns

Returns one of the following:

0

Everything ok.

1

The connection reconnected automatically.

-1

The server has gone away, and the connection is dead.


See also

is_open()


Method affected_rows

int affected_rows()

Description

Returns the number of rows affected by the last query.


Method insert_id

int insert_id()

Description

Returns the id of the last INSERT query into a table with an AUTO INCREMENT field.


Method error

string error()

Description

Returns a string describing the last error from the Mysql-server.

Returns 0 (zero) if there was no error.


Method select_db

void select_db(string database)

Description

Select database.

The Mysql-server can hold several databases. You select which one you want to access with this function.

See also

create() , create_db() , drop_db()


Method create_db

void create_db(string database)

Description

Create a new database

This function creates a new database named database in the Mysql-server.

See also

select_db() , drop_db()


Method drop_db

void drop_db(string database)

Description

Drop a database

This function drops the database named database from the Mysql-server.

See also

create_db() , select_db()


Method shutdown

void shutdown()

Description

Shutdown the Mysql-server

This function shuts down a running Mysql-server.

See also

reload()


Method reload

void reload()

Description

Reload security tables

This function causes the Mysql-server to reload its access tables.

See also

shutdown()


Method statistics

string statistics()

Description

Some Mysql-server statistics

This function returns some server statistics.

See also

server_info() , host_info() , protocol_info()


Method server_info

string server_info()

Description

Get the version number of the Mysql-server.

See also

statistics() , host_info() , protocol_info()


Method host_info

string host_info()

Description

Get information about the Mysql-server connection

See also

statistics() , server_info() , protocol_info()


Method protocol_info

int protocol_info()

Description

Give the Mysql protocol version

This function returns the version number of the protocol the Mysql-server uses.

See also

statistics() , server_info() , host_info()


Method list_dbs

Mysql.mysql_result list_dbs()
Mysql.mysql_result list_dbs(string wild)

Description

List databases

Returns a table containing the names of all databases in the Mysql-server. If the argument wild is specified, only those matching it will be returned.

See also

list_tables() , list_fields() , list_processes() , Mysql.mysql_result


Method list_tables

Mysql.mysql_result list_tables()
Mysql.mysql_result list_tables(string wild)

Description

List tables in the current database

Returns a table containing the names of all tables in the current database. If the argument wild is given, only those matching it will be returned.

See also

list_dbs() , list_fields() , list_processes() , Mysql.mysql_result


Method list_fields

array(int|mapping(string:mixed)) list_fields(string table)
array(int|mapping(string:mixed)) list_fields(string table, string wild)

Description

List all fields.

Returns an array of mappings with information about the fields in the table named table . If the argument wild is given, only those fields matching it will be returned

The mappings contain the following entries:

"name" : string

The name of the field.

"table" : string

The name of the table.

"default" : string

The default value for the field.

"type" : string

The SQL type of the field.

"length" : int

The length of the longest possible value that can be stored in the field. Note that this measures the display length in string form.

"flags" : multiset(string)

Some flags.

decimals : int

The number of decimalplaces.


The type of the field can be any of: "decimal", "char", "short", "long", "float", "double", "null", "time", "longlong", "int24", "tiny blob", "medium blob", "long blob", "var string", "string" or "unknown".

The flags multiset can contain any of:

"primary_key"

This field is part of the primary key for this table.

"not_null"

This field may not be NULL.

"blob"

This field is a blob field.


Note

Michael Widenius recomends use of the following query instead: show fields in 'table' like "wild".

See also

list_dbs() , list_tables() , list_processes() , Mysql.mysql_result.fetch_field()


Method list_processes

Mysql.mysql_result list_processes()

Description

List all processes in the Mysql-server

Returns a table containing the names of all processes in the Mysql-server.

See also

list_dbs() , list_tables() , list_fields() , Mysql.mysql_result


Method binary_data

int binary_data()

Description

Inform if this version of Mysql.mysql supports binary data

This function returns non-zero if binary data can be reliably stored and retreived with this version of the mysql-module.

Usually, there is no problem storing binary data in mysql-tables, but data containing '\0' (NUL) couldn't be fetched with old versions (prior to 3.20.5) of the mysql-library.

  Module Postgres

  CLASS Postgres.postgres

Description

This is an interface to the Postgres database server using libpq. This module may or may not be available on your Pike, depending whether the appropriate include and library files could be found at compile-time. Note that you do not need to have a Postgres server running on your host to use this module: you can connect to the database over a TCP/IP socket.

Please notice that unless you wish to specifically connect to a Postgres server, you'd better use the Sql.Sql , which is a server-independent sql-server-class. The interfaces to all existing sql-classes are consistent. Using Sql.Sql ensures that your Pike applications will run with any supported SQL server without changing a single line of code, at least for most common (and simple) operations.

The program Postgres.postgres provides the raw interface to the database. Many functions are not available for this program. Therefore, its use is DEPRECATED. It is included in this documentation only for completeness' sake. Use Sql.postgres instead, or even better Sql.Sql

Note

This driver is based on libpq and is DEPRECATED. There is a newer driver called Sql.pgsql which is faster and more robust than this driver and does not depend on any libraries.

Note

There is no testsuite for this module, since to test anything would require a working Postgres server. You can try to use the included scripts in the "pike/src/modules/Postgres/extras" directory but you'll probably have to patch them to reflect your site's settings.

The behavior of the Postgres C API also depends on certain environment variables defined in the environment of the pike interpreter.

"PGHOST"

Sets the name of the default host to connect to. It defaults to "localhost"

"PGOPTIONS"

Sets some extra flags for the frontend-backend connection. DO NOT SET unless you're sure of what you're doing.

"PGPORT"

Sets the default port to connect to, otherwise it will use compile-time defaults (that is: the time you compiled the postgres library, not the Pike driver).

"PGTTY"

Sets the file to be used for Postgres frontend debugging. Do not use, unless you're sure of what you're doing.

"PGDATABASE"

Sets the default database to connect to.

"PGREALM"

Sets the default realm for Kerberos authentication. I never used this, so I can't help you.


Refer to the libpq documentation for further details.

See also

Sql.Sql , Sql.postgres , Sql.postgres_result


Variable version

string Postgres.postgres.version

Description

Should you need to report a bug to the author, please submit along with the report the driver version number, as returned by this call.


Method create

void Postgres.postgres()
void Postgres.postgres(string host, void|string database, void|int port)

Description

With no arguments, this function initializes (reinitializes if a connection had been previously set up) a connection to the Postgres backend. Since Postgres requires a database to be selected, it will try to connect to the default database. The connection may fail however for a variety of reasons, in this case the most likely of all is because you don't have enough authority to connect to that database. So use of this particular syntax is discouraged.

The host argument allows you to connect to databases residing on different hosts. If it is 0 or "", it will try to connect to localhost.

The database argument specifies the database to connect to. If 0 or "", it will try to connect to the default database.

Note

You need to have a database selected before using the sql-object, otherwise you'll get exceptions when you try to query it. Also notice that this function can raise exceptions if the db server doesn't respond, if the database doesn't exist or is not accessible by you.

You don't need bothering about syncronizing the connection to the database: it is automatically closed (and the database is sync-ed) when the object is destroyed.

See also

Sql.postgres , Sql.Sql , select_db


Method select_db

void select_db(string dbname)

Description

This function allows you to connect to a database. Due to restrictions of the Postgres frontend-backend protocol, you always have to be connected to a database, so in fact this function just allows you to connect to a different database on the same server.

Note

This function can raise exceptions if something goes wrong (backend process not running, not enough permissions..)

See also

create


Method big_query

Sql.postgres_result big_query(string sqlquery)

Description

This is the only provided interface which allows you to query the database. If you wish to use the simpler "query" function, you need to use the Sql.Sql generic sql-object.

It returns a postgres_result object (which conforms to the Sql.sql_result standard interface for accessing data). I recommend using query() for simpler queries (because it is easier to handle, but stores all the result in memory), and big_query for queries you expect to return huge amounts of data (it's harder to handle, but fectches results on demand).

Note

This function can raise exceptions.

The program Sql.postgres_result is a superset of the raw Postgres.postgres_result which does not do chunking to avoid excessive memory usage in case of large resultsets.

See also

Sql.Sql , Sql.sql_result


Method error

string error()

Description

This function returns the textual description of the last server-related error. Returns 0 if no error has occurred yet. It is not cleared upon reading (can be invoked multiple times, will return the same result until a new error occurs).

See also

big_query


Method reset

void reset()

Description

This function resets the connection to the backend. Can be used for a variety of reasons, for example to detect the status of a connection.

Note

This function is Postgres-specific, and thus it is not available through the generic SQL-interface.


Method _set_notify_callback

void _set_notify_callback()
void _set_notify_callback(function f)

Description

With Postgres you can associate events and notifications to tables. This function allows you to detect and handle such events.

With no arguments, resets and removes any callback you might have put previously, and any polling cycle.

With one argument, sets the notification callback (there can be only one for each sqlobject).

The callback function must return no value, and takes a string argument, which will be the name of the table on which the notification event has occurred. In future versions, support for user-specified arguments will be added.

Note

The Sql.postgres program adds support for automatic delivery of messages (see it for explanation on the inner workings of this feature).

This function is Postgres-specific, and thus it is not available through the generic SQL-interface

See also

Sql.postgres


Method host_info

string host_info()

Description

This function returns a string describing what host are we talking to, and how (TCP/IP or UNIX sockets).


Method affected_rows

int affected_rows()

Description

This function returns the number of rows affected by the last query.


Method _quote

string _quote(string s)

Description

Escape a string to prevent SQL injection, using the current connection's character encoding settings.

  CLASS Postgres.postgres_result

Description

Contains the result of a Postgres-query.

See also

Sql.postgres, Postgres.postgres, Sql.Sql, Sql.sql_result


Method create

void Postgres.postgres_result(object o)

Description

You can't create istances of this object yourself. The only way to create it is via a big_query to a Postgres database.


Method num_rows

int num_rows()

Description

Returns the number of rows in the result.


Method num_fields

int num_fields()

Description

Returns the number of fields in the result.


Method fetch_fields

array(mapping(string:mixed)) fetch_fields()

Description

Returns an array with an entry for each field, each entry is a mapping with the following fields:

"name" : string

Name of the column

"type" : int

The type ID of the field. This is the database's internal representation type ID.

"length" : int|string

Can be an integer (the size of the contents in bytes) or the word "variable".


Note

For char() fields, length is to be intended as the MAXIMUM length of the field. This is not part of the interface specifications in fact, but a driver-choice. In fact char() fields are for Postgres _FIXED_ length fields, and are space-padded. If CUT_TRAILING_SPACES is defined when the driver is compiled (default behavior) it will cut such spaces.


Method seek

void seek()

Description

Moves the result cursor (ahead or backwards) the specified number of rows. Notice that when you fetch a row, the cursor is automatically moved forward one slot.


Method fetch_row

array(string) fetch_row()

Description

Returns an array with the contents of the next row in the result. Advances the row cursor to the next row. Returns 0 at end of table.

Bugs

Since there's no generic way to know whether a type is numeric or not in Postgres, all results are returned as strings. You can typecast them in Pike to get the numeric value.

See also

seek()

  Module Gdbm

  CLASS Gdbm.gdbm


Method create

void Gdbm.gdbm(void|string file, void|string mode)

Description

Without arguments, this function does nothing. With one argument it opens the given file as a gdbm database, if this fails for some reason, an error will be generated. If a second argument is present, it specifies how to open the database using one or more of the follow flags in a string:

r

Open database for reading

w

Open database for writing

c

Create database if it does not exist

t

Overwrite existing database

f

Fast mode

s

Synchronous mode

l

Locking mode


The fast mode prevents the database from syncronizing each change in the database immediately. This is dangerous because the database can be left in an unusable state if Pike is terminated abnormally.

The default mode is "rwc".

Note

The gdbm manual states that it is important that the database is closed properly. Unfortunately this will not be the case if Pike calls exit() or returns from main(). You should therefore make sure you call close or destruct your gdbm objects when exiting your program. This will probably be done automatically in the future.


Method fetch
Method `[]

string fetch(string key)
string `[](string key)

Description

Return the data associated with the key 'key' in the database. If there was no such key in the database, zero is returned.


Method delete

int(0..1) delete(string key)

Description

Remove a key from the database. Returns 1 if successful, otherwise 0, e.g. when the item is not present or the database is read only.


Method firstkey

string firstkey()

Description

Return the first key in the database, this can be any key in the database.


Method nextkey

string nextkey(string key)

Description

This returns the key in database that follows the key 'key' key. This is of course used to iterate over all keys in the database.

Example

// Write the contents of the database for(key=gdbm->firstkey(); k; k=gdbm->nextkey(k)) write(k+":"+gdbm->fetch(k)+"\n");


Method `[]=

string `[]=(string key, string data)

Description

Associate the contents of 'data' with the key 'key'. If the key 'key' already exists in the database the data for that key will be replaced. If it does not exist it will be added. An error will be generated if the database was not open for writing.

Example

gdbm[key] = data;

Returns

Returns data on success.

See also

store()


Method store

int store(string key, string data)

Description

Associate the contents of 'data' with the key 'key'. If the key 'key' already exists in the database the data for that key will be replaced. If it does not exist it will be added. An error will be generated if the database was not open for writing.

Example

gdbm->store(key, data);

Returns

Returns 1 on success.

Note

Note that the returned value differs from that of `[]=() .

See also

`[]=()


Method reorganize

int reorganize()

Description

Deletions and insertions into the database can cause fragmentation which will make the database bigger. This routine reorganizes the contents to get rid of fragmentation. Note however that this function can take a LOT of time to run.


Method sync

void sync()

Description

When opening the database with the 'f' flag writings to the database can be cached in memory for a long time. Calling sync will write all such caches to disk and not return until everything is stored on the disk.


Method close

void close()

Description

Closes the database.