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

What you are probably looking for is the UNION command:

SELECT id, 'messages' as 'table' FROM messages 
  WHERE content LIKE '%keyword%' 
    OR title LIKE '%keyword%'
UNION
SELECT id, 'topics' as 'table' FROM topics
  WHERE content LIKE '%keyword%' 
    OR title LIKE '%keyword%'
UNION
SELECT id, 'comments' as 'table' FROM comments
  WHERE content LIKE '%keyword%' 
    OR title LIKE '%keyword%'