title: create function mysql error
body: <p>Here is my function</p>
  
  <pre><code>DELIMITER //
  CREATE FUNCTION specialUser(user INT) RETURNS user_id INT
  BEGIN
      DECLARE user_id INT DEFAULT 0;
      CASE 
       WHEN user = 1556 THEN SET user_id = 1001;
       WHEN user = 1018 THEN SET user_id = 1002;
       WHEN user = 3658 THEN SET user_id = 1003;
           ELSE SET user_id = user;
      END CASE;
   RETURN user_id;
  END//
  </code></pre>
  
  <p>I get error:</p>
  
  <p>You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'user_id INT
      BEGIN
          DECLARE user_id INT DEFAULT 0;
          CASE 
          ' at line 1</p>