(PHP 3, PHP 4, PHP 5)
mysql_errno -- Returns the numerical value of the error message from previous MySQL operationReturns the error number from the last MySQL function.
Errors coming back from the MySQL database backend no longer issue warnings. Instead, use mysql_errno() to retrieve the error code. Note that this function only returns the error code from the most recently executed MySQL function (not including mysql_error() and mysql_errno()), so if you want to use it, make sure you check the value before calling another MySQL function.
The MySQL connection. If the link identifier is not specified, the last link opened by mysql_connect() is assumed. If no such link is found, it will try to create one as if mysql_connect() was called with no arguments. If by chance no connection is found or established, an E_WARNING level warning is generated.
Returns the error number from the last MySQL function, or 0 (zero) if no error occurred.