Question

how do I get for output or to query the table where the rows is.
I need to know of the output the row include to which table.

sprinf(SELECT id,alias,title,id_category FROM blog_article 
UNION 
SELECT id,alias,title,id_category FROM forum_thread 
WHERE LOWER(title) LIKE '%s%%' LIMIT 5, $key);

Answer 1

sprinf(SELECT "blog_article" as tbl,id,alias,title,id_category FROM blog_article 
UNION 
SELECT "forum_thread" as tbl,id,alias,title,id_category FROM forum_thread 
WHERE LOWER(title) LIKE '%s%%' LIMIT 5, $key);

The rows will have either blog_article or forum_thread as the first field “tbl” from which you can identify which table the row came from