PHP mysql search multiple tables using a keyword

Question

I have three tables in my database which are:

messages
topics
comments

Each of these tables has two fields called \'content\' and \'title\'

Answer 1

Two search in other tables you use:

SELECT `categories`.`title`, `posts`.`title` WHERE `categories`.`title` LIKE {$a} OR `posts`.`title` LIKE {$a}

The CATEGORIES and POSTS are tables of your database.