using LIKE %% with LEFT JOIN

Question

Ok, i used "LIKE" with "LEFT JOIN" and it works fine.

$sql = $conn->query("SELECT * FROM tasks t 
                     LEFT JOIN users u 
                     ON t.allowed_countries LIKE u.country 
                     WHERE u.username = '$username'");

but when i'm try to use "LIKE %%" instead of using "LIKE" then it gives me error

LIKE '%" u.country "%'

Can anybody tell me the problem please?

Thank you.

Answer 1

USE concat as％是一个char字面值。

LIKE concat('%',u.country,'%')