Find exact and partial matches in the tables I have two tables products and users. I need to find exact and partial matches in these tables. 

For example, there is a user with the username cat, and there is a product with the name cat. And there are products with the names of a good cat, red cat.

I want to get exact matches and partial matches. That is, get a user and three products.

I tried to do so, but the query returns an empty body.

SELECT P.*, U.*
    FROM PRODUCTS AS P
        LEFT JOIN USERS AS U ON (U.USER_ID = P.STORE_ID)
            WHERE 
                P.PRODUCT_NAME = 'cat' OR P.PRODUCT_NAME LIKE ('%cat%')
                AND U.USERNAME = 'cat' OR U.USERNAME LIKE ('%cat%')
                    GROUP BY P.PRODUCT_ID, U.USER_ID


How do I get a user and products for the word cat? Partial and exact matches.
use OR instead of AND, also 'cat' is LIKE '%cat% so you do not need to check with = also 

SELECT P.*, U.*
    FROM PRODUCTS AS P
        LEFT JOIN USERS AS U ON (U.USER_ID = P.STORE_ID)
            WHERE P.PRODUCT_NAME LIKE ('%cat%')
               OR U.USERNAME LIKE ('%cat%')
                    GROUP BY P.PRODUCT_ID, U.USER_ID