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mysql_insert_id
Synopsis
int mysql_insert_id([connection]);
mysql link connection
(optional): Connection handle returned by mysql_connect() or mysql_pconnect()
Description
mysql_insert_id() returns the AUTO_INCREMENT value (if any) generated by the last query made by the script calling mysql_insert_id() . If the connection() argument is not set, the last connection opened is used by default.
Note
mysql_insert_id() only returns a value if the last query on the specified connection handle caused an AUTO_INCREMENT column to generate a value. If you want to get the last AUTO_INCREMENT value generated, use the MySQL function LAST_INSERT_ID() . For example:
echo @ mysql_result (mysql_query ('SELECT LAST_INSERT_ID()'));
Note
mysql_insert_id() also returns the value for the last usage of 'LAST_INSERT_ID(number)'. For example, you can emulate sequences by doing this: 'UPDATE sequence SET id=LAST_INSERT_ID(id+1)' (For more information, see the MySQL manual.)
Caution
PHP converts AUTO_INCREMENT values to longs. If you're using an AUTO_INCREMENT column of type BIGINT, use the MySQL function LAST_INSERT_ID() to get the accurate AUTO_INCREMENT value.
In all cases except when using BIGINT, LAST_INSERT_ID() should return the same value as mysql_insert_id() .
Example
Example 817. Get the AUTO_INCREMENT ID generated by the last query
<?php
// Included code that connects to a MySQL server and sets a default database
// See the MySQL Functions chapter introduction for the source code for the file
include ('mysql_connect.inc.php');
// A SELECT query using a column name and a few functions
$query = "INSERT INTO user (login, password) VALUES ('jim', password('beammeupscotty'))";
// Run the query
$mysql_result = @ mysql_query ($query)
or die ("The query failed, but I shouldn't show you the error message - "
. "it would give away the user's password.");
// Check whether a value was generated by an AUTO_INCREMENT column in the last query
$last_id = mysql_insert_id ();
if ($last_id) {
echo "The last query generated an AUTO_INCREMENT value of $last_id";
} else {
echo "The last query did not generate an AUTO_INCREMENT value";
}
?>