How to use an user variables in MySQL LIKE clause?

SET @email = '[email protected]';

SELECT email from `user` WHERE email LIKE CONCAT('%', @email, '%');

You may have error

Error Code: 1267. Illegal mix of collations for operation 'like'    0.016 sec

In this case you need to specify the same collation as used for your table like that:

SET @email = '[email protected]' COLLATE utf8_unicode_ci;