mysql: CONCAT_WS to select from other table

Question

Normally we use concat_ws to join 2 field into 1 string on same table, how do i put a query to select the field value from other table?

GROUP_CONCAT(CONCAT_WS(' - ', item1_from_this_table, item_2_from_other_table) SEPARATOR '\n')

is it possible?

Answer 1

Join the tables and then (if otherwise ambiguous) table-qualify your column references:

SELECT GROUP_CONCAT(
         CONCAT_WS(' - ', t1.item, t2.item)
         SEPARATOR '\n'
       )
FROM   t1 JOIN t2 ON ...