Maybe something like this?
SELECT p.title, p.model_no,
b.brand_name,
c.category_title,
s.specification_title
FROM tbl_product AS p
LEFT JOIN tbl_brand AS b ON b.id = p.brand_id
LEFT JOIN tbl_category AS c ON c.id = p.category_id
LEFT JOIN tbl_product_specification AS s ON s.product_id = p.id
WHERE p.title LIKE 'keyword'
OR p.model_no LIKE 'keyword'
OR b.brand_name LIKE 'keyword'
OR c.category_title LIKE 'keyword'
OR s.specification_title LIKE 'keyword'
1
solved How to get search result by a keyword from different table in MySQL for php? [closed]