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PostgreSQL Functions

Введение

PostgreSQL database is Open Source product and available without cost. Postgres, developed originally in the UC Berkeley Computer Science Department, pioneered many of the object-relational concepts now becoming available in some commercial databases. It provides SQL92/SQL99 language support, transactions, referential integrity, stored procedures and type extensibility. PostgreSQL is an open source descendant of this original Berkeley code.

Требования

To use PostgreSQL support, you need PostgreSQL 6.5 or later, PostgreSQL 8.0 or later to enable all PostgreSQL module features. PostgreSQL supports many character encodings including multibyte character encoding. The current version and more information about PostgreSQL is available at » https://www.postgresql.org/ and the » PostgreSQL Documentation.

Установка

In order to enable PostgreSQL support, --with-pgsql[=DIR] is required when you compile PHP. DIR is the PostgreSQL base install directory, defaults to /usr/local/pgsql. If shared object module is available, PostgreSQL module may be loaded using extension directive in php.ini or dl() function.

Настройка во время выполнения

Поведение этих функций зависит от установок в php.ini.

PostgreSQL configuration options
Name Default Changeable Changelog
pgsql.allow_persistent "1" PHP_INI_SYSTEM  
pgsql.max_persistent "-1" PHP_INI_SYSTEM  
pgsql.max_links "-1" PHP_INI_SYSTEM  
pgsql.auto_reset_persistent "0" PHP_INI_SYSTEM Available since PHP 4.2.0.
pgsql.ignore_notice "0" PHP_INI_ALL Available since PHP 4.3.0.
pgsql.log_notice "0" PHP_INI_ALL Available since PHP 4.3.0.
Для подробного описания констант PHP_INI_*, обратитесь к документации функции ini_set().

Краткое разъяснение конфигурационных директив.

pgsql.allow_persistent boolean

Whether to allow persistent Postgres connections.

pgsql.max_persistent integer

The maximum number of persistent Postgres connections per process.

The maximum number of Postgres connections per process, including persistent connections.

pgsql.auto_reset_persistent integer

Detect broken persistent links with pg_pconnect(). Needs a little overhead.

pgsql.ignore_notice integer

Whether or not to ignore PostgreSQL backend notices.

pgsql.log_notice integer

Whether or not to log PostgreSQL backends notice messages. The PHP directive pgsql.ignore_notice must be off in order to log notice messages.

Типы ресурсов

There are two resource types used in the PostgreSQL module. The first one is the link identifier for a database connection, the second a resource which holds the result of a query.

Предопределенные константы

Перечисленные ниже константы определены данным расширением и могут быть доступны только в том случае, если PHP был собран с поддержкой этого расширения или же в том случае, если данное расширение подгружается во время выполнения.

PGSQL_ASSOC (integer)
Passed to pg_fetch_array(). Return an associative array of field names and values.
PGSQL_NUM (integer)
Passed to pg_fetch_array(). Return a numerically indexed array of field numbers and values.
PGSQL_BOTH (integer)
Passed to pg_fetch_array(). Return an array of field values that is both numerically indexed (by field number) and associated (by field name).
PGSQL_CONNECT_FORCE_NEW (integer)
Passed to pg_connect() to force the creation of a new connection, rather then re-using an existing identical connection.
PGSQL_CONNECTION_BAD (integer)
Returned by pg_connection_status() indicating that the database connection is in an invalid state.
PGSQL_CONNECTION_OK (integer)
Returned by pg_connection_status() indicating that the database connection is in a valid state.
PGSQL_SEEK_SET (integer)
Passed to pg_lo_seek(). Seek operation is to begin from the start of the object.
PGSQL_SEEK_CUR (integer)
Passed to pg_lo_seek(). Seek operation is to begin from the current position.
PGSQL_SEEK_END (integer)
Passed to pg_lo_seek(). Seek operation is to begin from the end of the object.
PGSQL_EMPTY_QUERY (integer)
Returned by pg_result_status(). The string sent to the server was empty.
PGSQL_COMMAND_OK (integer)
Returned by pg_result_status(). Successful completion of a command returning no data.
PGSQL_TUPLES_OK (integer)
Returned by pg_result_status(). Successful completion of a command returning data (such as a SELECT or SHOW).
PGSQL_COPY_OUT (integer)
Returned by pg_result_status(). Copy Out (from server) data transfer started.
PGSQL_COPY_IN (integer)
Returned by pg_result_status(). Copy In (to server) data transfer started.
PGSQL_BAD_RESPONSE (integer)
Returned by pg_result_status(). The server's response was not understood.
PGSQL_NONFATAL_ERROR (integer)
Returned by pg_result_status(). A nonfatal error (a notice or warning) occurred.
PGSQL_FATAL_ERROR (integer)
Returned by pg_result_status(). A fatal error occurred.
PGSQL_TRANSACTION_IDLE (integer)
Returned by pg_transaction_status(). Connection is currently idle, not in a transaction.
PGSQL_TRANSACTION_ACTIVE (integer)
Returned by pg_transaction_status(). A command is in progress on the connection. A query has been sent via the connection and not yet completed.
PGSQL_TRANSACTION_INTRANS (integer)
Returned by pg_transaction_status(). The connection is idle, in a transaction block.
PGSQL_TRANSACTION_INERROR (integer)
Returned by pg_transaction_status(). The connection is idle, in a failed transaction block.
PGSQL_TRANSACTION_UNKNOWN (integer)
Returned by pg_transaction_status(). The connection is bad.
PGSQL_DIAG_SEVERITY (integer)
Passed to pg_result_error_field(). The severity; the field contents are ERROR, FATAL, or PANIC (in an error message), or WARNING, NOTICE, DEBUG, INFO, or LOG (in a notice message), or a localized translation of one of these. Always present.
PGSQL_DIAG_SQLSTATE (integer)
Passed to pg_result_error_field(). The SQLSTATE code for the error. The SQLSTATE code identifies the type of error that has occurred; it can be used by front-end applications to perform specific operations (such as error handling) in response to a particular database error. This field is not localizable, and is always present.
PGSQL_DIAG_MESSAGE_PRIMARY (integer)
Passed to pg_result_error_field(). The primary human-readable error message (typically one line). Always present.
PGSQL_DIAG_MESSAGE_DETAIL (integer)
Passed to pg_result_error_field(). Detail: an optional secondary error message carrying more detail about the problem. May run to multiple lines.
PGSQL_DIAG_MESSAGE_HINT (integer)
Passed to pg_result_error_field(). Hint: an optional suggestion what to do about the problem. This is intended to differ from detail in that it offers advice (potentially inappropriate) rather than hard facts. May run to multiple lines.
PGSQL_DIAG_STATEMENT_POSITION (integer)
Passed to pg_result_error_field(). A string containing a decimal integer indicating an error cursor position as an index into the original statement string. The first character has index 1, and positions are measured in characters not bytes.
PGSQL_DIAG_INTERNAL_POSITION (integer)
Passed to pg_result_error_field(). This is defined the same as the PG_DIAG_STATEMENT_POSITION field, but it is used when the cursor position refers to an internally generated command rather than the one submitted by the client. The PG_DIAG_INTERNAL_QUERY field will always appear when this field appears.
PGSQL_DIAG_INTERNAL_QUERY (integer)
Passed to pg_result_error_field(). The text of a failed internally-generated command. This could be, for example, a SQL query issued by a PL/pgSQL function.
PGSQL_DIAG_CONTEXT (integer)
Passed to pg_result_error_field(). An indication of the context in which the error occurred. Presently this includes a call stack traceback of active procedural language functions and internally-generated queries. The trace is one entry per line, most recent first.
PGSQL_DIAG_SOURCE_FILE (integer)
Passed to pg_result_error_field(). The file name of the PostgreSQL source-code location where the error was reported.