Unknown Column In Where Clause
SQL is evaluated backwards, from right to left. So the where clause is parsed and evaluate prior to the select clause. Because of this the aliasing of u_name to user_name has not yet occurred.
mysql-error-1054
Unknown column in ‘field list’ error on MySQL Update query
Try using different quotes for “y” as the identifier quote character is the backtick (“`”). Otherwise MySQL “thinks” that you point to a column named “y”. See also MySQL 5 Documentation
Unknown column in ‘field list’ error on MySQL Update query
Try using different quotes for “y” as the identifier quote character is the backtick (“`”). Otherwise MySQL “thinks” that you point to a column named “y”. See also MySQL 5 Documentation