Question

I have 2 tables like so:

-----------------------------------------------------
| PLACES                                            |
-----------------------------------------------------
| Id             | Name          | Address          |
-----------------------------------------------------
| 1              | Parc          | 20 King St       |
| 2              | Bar           | 33 Main St       |
-----------------------------------------------------

-----------------------------------------------------
| PEOPLE                                            |
-----------------------------------------------------
| Id             | Place_id (fk) | Name             |
-----------------------------------------------------
| 1              | 2             | Luke             |
| 2              | 1             | Han              |
| 3              | 1             | Chewie           |
-----------------------------------------------------

I want to display every places with their associated people. To do so I though it would be great to have a single record per place with an list of people (instead of having the same place for each people entry).

I’m really not familiar with SQL queries so I tried using Right Join and Group By without any positive results.

SELECT plc.name, plc.address, plp.name 
        FROM places plc
            RIGHT JOIN people plp
                ON plp.place_id = plc.id
                    GROUP BY plc.name;

The results I got after doing “$query->fetchAll();” in PHP were something like that:

Object {name: "Bar", address: "33 Main St", name: "Luke"}
Object {name: "Parc", address: "20 King St", name: "Han"}
Object {name: "Parc", address: "20 King St", name: "Chewie"}

I guess the best solution possible would be to have something filtered like that, which would prevent additional work both from the backend and frontend side. However, I have absolutely no idea if it’s possible:

Object {name: "Bar", address: "33 Main St", name: "Luke"}
Object {name: "Parc", address: "20 King St", name: ["Han", "Chewie"]}

Any advices or suggestions on how I could achieve this? Thanks!

Answer 1

easiest way would be to use group_concat

select
  place.id as `Id`,
  place.address as `address`,
  GROUP_CONCAT(people.name) as `peopleList`
from
  place,
  peoples
where
  place.id=people.place_id
group by
  place.id

and, if you see your results getting cropped, you can increase the size limit of GROUP_CONCAT like this:

SET SESSION group_concat_max_len = 8192;