Use a comma-separated string in an `IN ()` in MySQL

Question

If a user-defined variable @x is a string of comma separated numbers, e.g. '1,2,4', is there a way to use it in an IN () function?

Specifically:

SET @x := '1,2,4';
SELECT * FROM t WHERE c IN (@x);

does not select rows in t where c equals 1 or 2 or 4.

Answer 1

You can't do this directly using a variable. Based on what you have now, the server is trying to execute select * form t where c in ('1,2,3'); ... which clearly isn't what you want given that you're checking to see if c contains the single string given.

You must generate dynamic SQL based off of your list in order to get this to work.

Answer 2

Maybe there is no point of answering this question now, but recently I faced same problem and this is how I resolved it.

It worked for me, hope this is what you were looking for.

select * from table_name where CONCAT(',',('1,2,4'),',') LIKE CONCAT('%,',column_name,',%');

Example: It will look like this

select * from t where ',1,2,4,' LIKE '%,2,%';