Aggregate Functions Trong Postgres1.String_agg ID COMPANY_ID EMPLOYEE 1 1 Anna 2 1 Bill 3 2 Carol 4 2 Dave SELECT company_id, string_agg(employee, ', ') FROM mytable GROUP BY company_id; COMPANY_ID EMPLOYEE 1 An...Jul 10, 2021 · 1 min readthanhbn.hashnode.dev