Delete with Join in MySQL

Question

Here is the script to create my tables:

CREATE TABLE clients (
   client_i INT(11),
   PRIMARY KEY (client_id)
);
CREATE TABLE projects (
   project_id INT(         


        

Answer 1

Another method of deleting using a sub select that is better than using IN would be WHERE EXISTS

DELETE  FROM posts
WHERE   EXISTS ( SELECT  1 
                 FROM    projects
                 WHERE   projects.client_id = posts.client_id);

One reason to use this instead of the join is that a DELETE with JOIN forbids the use of LIMIT. If you wish to delete in blocks so as not to produce full table locks, you can add LIMIT use this DELETE WHERE EXISTS method.