(no version information, might be only in CVS)

pg_send_prepare -- Asynchronously prepares a query for future execution


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().


Exemple 1. Using pg_send_prepare()

= 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);

Voir aussi