How to fix this query? Using GROUP_CONCAT

Question

I have a query that would get all product names and concatenate the names to 1 column. But I can't figure out how to make it work. Here is the query.

SELECT package_id, 
GROUP_CONCAT
(
    SELECT c.product_name FROM tbl_product c WHERE c.product_id IN 
    (
        SELECT a.product_id FROM tbl_package_detail a WHERE a.package_id = b.package_id
    ) 
    ORDER BY c.product_id
)
FROM tbl_package b
GROUP BY package_id

Note that:

SELECT c.product_name FROM tbl_product c WHERE c.product_id IN 
(
    SELECT a.product_id FROM tbl_package_detail a WHERE a.package_id = b.package_id
) 
ORDER BY c.product_id

Returns all the product names I need. I am not sure if I am using GROUP_CONCAT correctly.

ERROR MESSAGE:

You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near ' SELECT c.product_name FROM tbl_product c WHERE c.product_id IN '

Answer 1

Try the following

SELECT
  b.package_id, 
  GROUP_CONCAT(c.product_name ORDER BY c.product_id) ProductList
FROM tbl_package b
LEFT JOIN tbl_package_detail a ON a.package_id = b.package_id
LEFT JOIN tbl_product c ON c.product_id=a.product_id
GROUP BY b.package_id

GROUP_CONCAT is an aggregate function like SUM/AVG/MIN/MAX/COUNT .