Getting "Scalar subquery produced more than one element" Error

Question

SELECT
  CONCAT(warehouse.warehouse_id,warehouse.warehouse_alias) AS warehouse_name,
  (SELECT
  COUNT(*)
    FROM focused-mote-392209.warehouse_orders.orders AS orders
    GROUP BY
    orders.warehouse_id
  ) AS total_orders,
FROM
  focused-mote-392209.warehouse_orders.warehouse AS warehouse
INNER JOIN
  focused-mote-392209.warehouse_orders.orders AS orders 
  ON warehouse.warehouse_id = orders.warehouse_id
GROUP BY
warehouse_name

I want to group orders by warehouses but when i run this query i get "Scalar subquery produced more than one element" error. How can i fix this?

I've tried to group orders at the end of query but that time i couldn't group the things i wanted to select such as "warehouse_id" and "warehouse_alias" so i've tried using concat.

Answer 1

Try this:

SELECT
  CONCAT(warehouse.warehouse_id,warehouse.warehouse_alias) AS warehouse_name,
  COUNT(orders.warehouse_i) AS total_orders
FROM
  focused-mote-392209.warehouse_orders.warehouse AS warehouse
INNER JOIN
  focused-mote-392209.warehouse_orders.orders AS orders 
  ON warehouse.warehouse_id = orders.warehouse_id
GROUP BY
warehouse_name