Error number displaying after execution of a query
MySQL query on error returns an error number for reference. This error number can be collected or can be further processed as per requirement. Even we can post the error number along with error message to an email address. Getting the error number is simple. We have to use mysql_errno() function. Please note that this command will return the error number associated with most recent MySQL query. It will return zero if no error is associated.
So we have to check this before going to next mysql query. Printing error message along with error number is a good idea.
Here is an example of this error number. Let us see what error we will get in case of generated error out of one non existence field name called in an mysql select query.
$querry = mysql_query("SELECT new_field FROM student");
echo "Error Number= ".mysql_errno(); // will print 1054
In the above table student new_field is a non existence field or column.
Error Number for PHP PDO
We will be using PDO for connecting and using MySQL database from PHP. PDO has errorCode() function to display error numbers.
Here is the code to display error number
$pdo=$dbo->prepare('Select * from nonexistence_table');
if($pdo->execute()){
echo 'Success<br>';
}else{
print_r($pdo->errorCode());
}