pg_send_prepare
(no version information, might be only in CVS)
pg_send_prepare -- Asynchronously prepares a query for future execution
Description
resource
pg_send_prepare ( string stmtname, string query )
resource
pg_send_prepare ( resource connection, string stmtname, string query )
pg_send_prepare() asynchronously prepares a query
on the connection. Unlike pg_prepare(),
script execution is not blocked while the query is being prepared. It
behaves in the same fashion as pg_send_query().
Parameters to pg_prepare() are specified
using placeholders in the query. It is not necessary to quote
parameters as quoting and escaping is done automatically.
Placeholders are indicated in the query
by $1, $2, $3 and so on.
Using prepared queries means you can prepare one and
then execute many times, with different parameters. PostgreSQL
will cache the query plan on the prepare, then re-use it for
each execute, resulting in speed improvements. There is no
need to use a prepared query if it will only be executed once.
In this case, it is simpler to use pg_query_params().
Examples
Example 1. Using pg_send_prepare()
<?php
$dbconn = pg_connect("dbname=publisher") or die("Could not connect");
// Prepare a query for execution
if (!pg_connection_busy($dbconn)) {
pg_send_prepare($dbconn, "my_query", 'SELECT * FROM shops WHERE name = $1');
$res1 = pg_get_result($dbconn);
}
// Execute the prepared query. Note that it is not necessary to escape
// the string "Joe's Widgets" in any way
if (!pg_connection_busy($dbconn)) {
pg_send_execute($dbconn, "my_query", array("Joe's Widgets"));
$res2 = pg_get_result($dbconn);
}
// Execute the same prepared query, this time with a different parameter
if (!pg_connection_busy($dbconn)) {
pg_send_execute($dbconn, "my_query", array("Clothes Clothes Clothes"));
$res3 = pg_get_result($dbconn);
}
?>
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