Используемые операторы SELECT имеют разное количество столбцов (SQL), НО ПОЧЕМУ [закрыто] ⇐ Php

[Anonymous]

Код: Выделить всё

SELECT
Date, T1_Client_name, T1_details, T1_Target, T2_Achieve
FROM
(SELECT
target.target_date as Date, target.target_id, target.customer_name as T1_Client_name, target.target_product as T1_details, target.target_pay as T1_Target, NULL AS T2_Achieve
FROM
target_value AS target

UNION ALL
SELECT
order_item.order_id, NULL as T1_Client_name, NULL AS details,  NULL as T1_Target, quantity AS T2_Achieve
FROM
order_item) AS order_item
LEFT JOIN
( SELECT
NULL AS Date, orders.order_id, orders.client_name, NULL as T1_Client_name, NULL AS details,  NULL as T1_Target, NULL AS T2_Achieve
FROM
orders) AS orders ON orders.order_id = order_item.order_id
LEFT JOIN
(SELECT
customer.customer_id,  customer.customer_name
FROM
customer) AS customer ON customer.customer_id = orders.client_name
ORDER BY
Date ASC ;

MySQL сказал: Документация
#1222 – Используемые операторы SELECT имеют разное количество столбцов
пожалуйста, расскажите мне о моей ошибке?

Подробнее здесь: https://stackoverflow.com/questions/790 ... ql-but-why