sql - MySQL automatic string to integer casting in where clause?

Question

I am not new to MySQL but a strange situation happened in my code today coincidently which got me surprised. Can someone explain why this gives me identical results?

SELECT * FROM `products` WHERE id = 12

and

SELECT * FROM `products` WHERE id = '12ABC'

In both cases I get the same result with the same record being selected. I would expect that second one would return me nothing?! My ID field is int(11) unsigned with auto_increment flag turned on.

Answer 1

From MySQL docs:

When an operator is used with operands of different types, type conversion occurs to make the operands compatible

Documentation

So basically, '12ABC' is cast to 12.