Is it possible to write function like SUM() but for strings?
I have a table categories with fields id, name, parent_id
and I need a query something like this:
select *, STR_SUM(category.name) as cat_name from categories
group by category.parent_id
where STR_SUM() - a function for string concatenation.
It has to return a list like this: 'cat1, cat2, cat3'