How to use WHERE IN in subquery with value from string column? - mysql

Question

I have a problem to use WHERE IN with a column value
I have data like below
Table Service
id name sd_ids
1 House Cleaning 1,2
Table Service Detail
id name
1 living room
2 bedroom
Schema
CREATE TABLE IF NOT EXISTS `service` (
`id` int(6) unsigned NOT NULL,
`name` varchar(200) NOT NULL,
`sd_ids` varchar(200) NOT NULL,
PRIMARY KEY (`id`)
) DEFAULT CHARSET=utf8;
INSERT INTO `service` (`id`, `name`,`sd_ids`) VALUES
('1','House Cleaning','1,2');
CREATE TABLE IF NOT EXISTS `service_detail` (
`id` int(6) unsigned NOT NULL,
`name` varchar(200) NOT NULL,
PRIMARY KEY (`id`)
) DEFAULT CHARSET=utf8;
INSERT INTO `service_detail` (`id`, `name`) VALUES
('1','living room'),
('2','bedroom');
I already tried this
SELECT *,
(
SELECT
GROUP_CONCAT(name)
from service_detail
where id in(service.sd_ids)
) as service_detail
FROM service;
but the result it's not what I want
id name sd_ids service_detail
1 House Cleaning 1,2 living
I put schema and my testing here
http://sqlfiddle.com/#!9/49c34e/7
What I want to achieve to shows the result like below
id name sd_ids service_detail
1 House Cleaning 1,2 living room,bedroom
I know this schema is not best practice, but I need suggestion to achieve that.
thanks

Answer 1

You may join using FIND_IN_SET in the join criteria:
SELECT
s.id,
s.name,
s.sd_ids,
GROUP_CONCAT(sd.name ORDER BY sd.id) AS service_detail
FROM service s
INNER JOIN service_detail sd
ON FIND_IN_SET(sd.id, s.sd_ids) > 0
GROUP BY
s.id,
s.name,
s.sd_ids;
Demo
In general you should avoid storing CSV data in your SQL tables. CSV data represents unnormalized data, and is difficult to work with (q.v. the above query). Instead, break every service ID onto a separate record for best results.