PostgreSQL Functions
PHP Manual

pg_prepare

Submits a request to the server to create a prepared statement with the given parameters, and waits for completion

Description

PgSql\Resultfalse pg_prepare(PgSql\Connection $connection = ?, string $stmtname, string $query)

pg_prepare creates a prepared statement for later execution with pg_execute or pg_send_execute. This feature allows commands that will be used repeatedly to be parsed and planned just once, rather than each time they are executed. pg_prepare is supported only against PostgreSQL 7.4 or higher connections; it will fail when using earlier versions.

The function creates a prepared statement named stmtname from the query string, which must contain a single SQL command. stmtname may be "" to create an unnamed statement, in which case any pre-existing unnamed statement is automatically replaced; otherwise it is an error if the statement name is already defined in the current session. If any parameters are used, they are referred to in the query as $1, $2, etc.

Prepared statements for use with pg_prepare can also be created by executing SQL PREPARE statements. (But pg_prepare is more flexible since it does not require parameter types to be pre-specified.) Also, although there is no PHP function for deleting a prepared statement, the SQL DEALLOCATE statement can be used for that purpose.

Parameters

connection

An PgSql\Connection instance. When connection is unspecified, the default connection is used. The default connection is the last connection made by pg_connect or pg_pconnect.

Warning

As of PHP 8.1.0, using the default connection is deprecated.

stmtname

The name to give the prepared statement. Must be unique per-connection. If "" is specified, then an unnamed statement is created, overwriting any previously defined unnamed statement.

query

The parameterized SQL statement. Must contain only a single statement (multiple statements separated by semi-colons are not allowed). If any parameters are used, they are referred to as $1, $2, etc.

Return Values

An PgSql\Result instance on success, or false on failure.

Changelog

Version Description
8.1.0 Returns an PgSql\Result instance now; previously, a resource was returned.
8.1.0 The connection parameter expects an PgSql\Connection instance now; previously, a resource was expected.

Examples

Example #1 Using pg_prepare

<?php

// Connect to a database named "mary"
$dbconn = pg_connect("dbname=mary");

// Prepare a query for execution
$result = pg_prepare($dbconn, "my_query", 'SELECT * FROM shops WHERE name = $1');

// Execute the prepared query.  Note that it is not necessary to escape
// the string "Joe's Widgets" in any way
$result = pg_execute($dbconn, "my_query", array("Joe's Widgets"));

// Execute the same prepared query, this time with a different parameter
$result = pg_execute($dbconn, "my_query", array("Clothes Clothes Clothes"));

?>

See Also

  • pg_execute
  • pg_send_execute