Question

I want to perform a conditional right join in this SQL

SELECT *
 FROM   post
   IF   1 = 1 THEN RIGHT JOIN faves ON faves.post_id_fk = post_id;  // <== error
END IF;
 WHERE  post_author_id
        LIKE 1
 ORDER  BY post_timestamp DESC
 LIMIT  0, 10

Is there a better/right way of doing this?

Answer 1

From where does your condition originate?

1. If it comes from outside of SQL, why not determine whether or not to put the join into your query at that level:

   $qry = "SELECT * FROM post " . ($test ? " RIGHT JOIN ... " : "") . "...";
   

2. Otherwise, if it must be tested within SQL, I’d separate the different statements apart:

   DELIMITER ;;
   
   IF @test THEN
       SELECT * FROM post RIGHT JOIN ... ;
   ELSE
       SELECT * FROM post ... ;
   END IF;;
   
   DELIMITER ;