Question

When I try to put a value into a DATE field which is invalid, MySQL seems to use 0000-00-00 instead. Is there a way I can do this “check” without updating a DATE field? And to do it from for example PHP?

Like, is there a way I can query the MySQL server and ask “Hey, is this DATE, TIME or DATETIME valid to you?”

Or is there maybe an even better way of doing it?

Answer 1

If you choose a server mode for the MySQL server that doesn’t allow invalid date values a query containing such a malformed date representation will cause an error instead of (silently) assuming 0000-00-00
see http://dev.mysql.com/doc/refman/5.0/en/server-sql-mode.html

e.g.

$pdo = new PDO('mysql:host=localhost;dbname=test', 'localonly', 'localonly'); 
$pdo->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );

$pdo->exec('CREATE TEMPORARY TABLE foo (id int auto_increment, d datetime, primary key(id))');

$query = "INSERT INTO foo (d) VALUES ('2010-02-31 12:15:18')";
foreach( array('ALLOW_INVALID_DATES', 'STRICT_ALL_TABLES') as $mode ) {
  echo $mode, ": "; flush();
  $pdo->exec("SET SESSION sql_mode='$mode'");
  $pdo->exec($query);
  echo "Ok.\n";
}

prints

ALLOW_INVALID_DATES: Ok.
STRICT_ALL_TABLES: 
Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[22007]: Invalid datetime format: 1292 Incorrect datetime value: '2010-02-31 12:15:18' for column 'd' at row 1' in [...]