MySQL Selecting records by multiple IDs with LIMIT per each ID 4

Question

I'm stuck with query. The scenario is like this: - I need to select max 4 product_name for each category. - I'm using this query but it doesn't work the way I need -each cat_id with product_name limit 4

the result will contain 4 lines from the whole query output.

   $sql_course = "SELECT * FROM product WHERE cat_id IN('".$brand_filter."') ORDER BY cat_id LIMIT 4";

i want this

cat_id1- product1
cat_id1- product2
cat_id1- product3
cat_id1- product4

cat_id2- product5
cat_id2- product6
cat_id2- product7
cat_id2- product8

Answer 1

限制正在影响您的输出，因为它只带来四个记录。

Answer 2

 $sql_course = "SELECT * FROM product WHERE cat_id IN('".$brand_filter."') GROUP BY cat_id ORDER BY cat_id LIMIT 4";

我想这会奏效，请尝试检查结果。