Mysql Like containing wildcart giving unexpected result

Question

I have a varchar column inside a very simple MySQL Database table that contains 2 different types of product references :

one like : 14521_451_288, and the others like 45742154

to be able to manage them, I'm using the following code :

WHERE ref LIKE '%_%'

But all the results are returned, even the references without underscore. Am I missing something basic here?

Answer 1

_ stand for any one character in a LIKE expression. That's why you return all values. You need to escape the _ character.

Try this:

WHERE ref LIKE '%\_%';

References:

String Literals on MySQL Reference Manual

Related SO question

Answer 2

Try using

where ref <> instr('_') > 0

because _ stands for any single character in the like expression while % stands for any characters in the expression.