pg_prepare

说明

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.

参数

返回值

A query result resource on success, or FALSE on failure.

例

例子 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")); ?>

参见