Many To Many Table Join With Pivot

Question

I currently have two tables similar to users and programs that are linked through a many-to-many relationships by way of a link table.

Answer 1

SELECT users.name, group_concat(programs.name) from linker
INNER JOIN users on linker.user_id = users.id
INNER JOIN programs on linker.program_id = programs.id
GROUP BY users.id;

Answer 2

You need to specify a DISTINCT, i.e.

select users.name, group_concat( DISTINCT programs.name)

See the MySQL docs here.

Try changing your query to:

SELECT users.name, group_concat(programs.name) 
from users
LEFT JOIN linker on linker.user_id = users.id
LEFT JOIN programs on linker.program_id = programs.id
GROUP BY users.id

This will give you a null for any user with no programs associated with them. To filter them out, just add a WHERE programs.id IS NOT NULL.