使用MySQLDb处理错误的日期值

I have a table that stores information as a set of name-value pairs. Some of the values are supposed to be dates, character encoded like 'YYYY-MM-DD', but I somehow got some bad data into my table. When I try to convert a bad entry to a date from the MySQL command line client I get a null. But when I try to do this using a Python program using MySQLDb it throws an exception like:I have a table that stores information as a set