(PHP 5)
mysqli->connect_errno -- mysqli_connect_errno — Returns the error code from last connect call
Returns the last error code number from the last call to mysqli_connect().
Note: Client error message numbers are listed in the MySQL errmsg.h header file, server error message numbers are listed in mysqld_error.h. In the MySQL source distribution you can find a complete list of error messages and error numbers in the file Docs/mysqld_error.txt.
An error code value for the last call to mysqli_connect(), if it failed. zero means no error occurred.
Example #1 mysqli_connect_errno() example
<?php
$link = @mysqli_connect("localhost", "nonexisting_user", "");
if (!$link) {
printf("Can't connect to localhost. Errorcode: %d\n", mysqli_connect_errno());
}
?>