(PHP 4, PHP 5)
mysql_affected_rows — Get number of affected rows in previous MySQL operation
Get the number of affected rows by the last INSERT, UPDATE, REPLACE or DELETE query associated with link_identifier .
Връзката към MySQL. Ако не е указана, се използва последната създадена връзка от mysql_connect(). Ако не намери такава връзка, ще направи опит да установи връзка, все едно е изпълнена mysql_connect() без параметри. Ако случайно не е намерена или създадена никаква връзка, ще се генерира предупреждение от ниво E_WARNING.
Returns the number of affected rows on success, and -1 if the last query failed.
If the last query was a DELETE query with no WHERE clause, all of the records will have been deleted from the table but this function will return zero with MySQL versions prior to 4.1.2.
When using UPDATE, MySQL will not update columns where the new value is the same as the old value. This creates the possibility that mysql_affected_rows() may not actually equal the number of rows matched, only the number of rows that were literally affected by the query.
The REPLACE statement first deletes the record with the same primary key and then inserts the new record. This function returns the number of deleted records plus the number of inserted records.
Example #1 mysql_affected_rows() example
<?php
$link = mysql_connect('localhost', 'mysql_user', 'mysql_password');
if (!$link) {
die('Could not connect: ' . mysql_error());
}
mysql_select_db('mydb');
/* this should return the correct numbers of deleted records */
mysql_query('DELETE FROM mytable WHERE id < 10');
printf("Records deleted: %d\n", mysql_affected_rows());
/* with a where clause that is never true, it should return 0 */
mysql_query('DELETE FROM mytable WHERE 0');
printf("Records deleted: %d\n", mysql_affected_rows());
?>
Примерът по-горе ще изведе нещо подобно на:
Records deleted: 10 Records deleted: 0
Example #2 mysql_affected_rows() example using transactions
<?php
$link = mysql_connect('localhost', 'mysql_user', 'mysql_password');
if (!$link) {
die('Could not connect: ' . mysql_error());
}
mysql_select_db('mydb');
/* Update records */
mysql_query("UPDATE mytable SET used=1 WHERE id < 10");
printf ("Updated records: %d\n", mysql_affected_rows());
mysql_query("COMMIT");
?>
Примерът по-горе ще изведе нещо подобно на:
Updated Records: 10
Забележка: Transactions
If you are using transactions, you need to call mysql_affected_rows() after your INSERT, UPDATE, or DELETE query, not after the COMMIT.
Забележка: SELECT Statements
To retrieve the number of rows returned by a SELECT, it is possible to use mysql_num_rows().