pdo免费结果

there is a mysql function in php called mysql_free_result(); I couln't find any similar function for PDO.

is there a pdo function to free the result of a database fetch or does the result set automatically get requested and freed when I call $stmt->fetch() data?

could someone explain me this difference between native mysql and pdo?

closest method is close cursor for PDO statements.

http://us.php.net/manual/en/pdostatement.closecursor.php

You can set the object variable to null. The GC will destroy the PDO Statement instance, I guess.