MySQL 中的 UNION 查询问题

Question

看看我的 UNION 查询：

SELECT customer_id
     , name as cname
     , CASE
        WHEN address <> ''
          THEN CONCAT(address, ', ', city)
        ELSE city
       END as address
     , null as total_sale
     , null as total_paid
     , null as total_due
FROM customer c

UNION 

SELECT customer_id
     , null as cname
     , null as address
     , sum(amount_due_tot) as total_sale
     , sum(amount_paid_tot) as total_paid
     , sum(amount_due_balance_tot) as total_due
FROM (
  SELECT bad.basket_id as baskets
       , bad.customer_id as customer_id
       , bad.amount_due as amount_due_tot
       , sum(COALESCE(p.amount_paid, 0)) as amount_paid_tot
       , bad.amount_due - SUM(COALESCE(p.amount_paid, 0)) as amount_due_balance_tot
       , sale_status_id
  FROM basket_amount_due bad
    LEFT JOIN basket b USING (basket_id)
    LEFT JOIN basket_payment p USING (basket_id)
    LEFT JOIN customer c ON b.customer_id = c.customer_id
  WHERE b.sale_status_id = 4
  GROUP BY basket_id, sale_status_id
) d
GROUP BY customer_id;

它returns结果如下所示：

+-------------+--------------------+-----------------+------------+------------+-----------+
| customer_id | cname              | address         | total_sale | total_paid | total_due |
+-------------+--------------------+-----------------+------------+------------+-----------+
|           1 | Customer Name 01   | NULL            |       NULL |       NULL |      NULL |
|           2 | Customer Name 02   | Address 02      |       NULL |       NULL |      NULL |
|           3 | Customer Name 03   | Address 03      |       NULL |       NULL |      NULL |
|           4 | Customer Name 04   | Address 04      |       NULL |       NULL |      NULL |
|           5 | Customer Name 05   | Address 05      |       NULL |       NULL |      NULL |
|           6 | Customer Name 06   |                 |       NULL |       NULL |      NULL |
|           7 | Customer Name 07   |                 |       NULL |       NULL |      NULL |
|           1 | NULL               | NULL            |     927.08 |     927.08 |      0.00 |
|           3 | NULL               | NULL            |    2576.80 |    2376.80 |    200.00 |
|           4 | NULL               | NULL            |   12118.00 |    4210.25 |   7907.75 |
|           6 | NULL               | NULL            |     870.00 |     270.00 |    600.00 |
+-------------+--------------------+-----------------+------------+------------+-----------+

但是从这个 UNION 查询我希望得到这个结果：

+-------------+--------------------+-----------------+------------+------------+-----------+
| customer_id | cname              | address         | total_sale | total_paid | total_due |
+-------------+--------------------+-----------------+------------+------------+-----------+
|           1 | Customer Name 01   | NULL            |     927.08 |     927.08 |      0.00 |
|           2 | Customer Name 02   | Address 02      |       NULL |       NULL |      NULL |
|           3 | Customer Name 03   | Address 03      |    2576.80 |    2376.80 |    200.00 |
|           4 | Customer Name 04   | Address 04      |   12118.00 |    4210.25 |   7907.75 |
|           5 | Customer Name 05   | Address 05      |     870.00 |     270.00 |    600.00 |
|           6 | Customer Name 06   |                 |       NULL |       NULL |      NULL |
|           7 | Customer Name 07   |                 |       NULL |       NULL |      NULL |
+-------------+--------------------+-----------------+------------+------------+-----------+

谁能告诉我我在这个查询中做错了什么？

Answer 1

您需要使用 join 而不是 union。

SELECT c.customer_id
     , c.name as cname
     , CASE
        WHEN address <> ''
          THEN CONCAT(c,address, ', ', c.city)
        ELSE city
       END as address
     , sum(d.amount_due_tot) as total_sale
     , sum(d.amount_paid_tot) as total_paid
     , sum(d.amount_due_balance_tot) as total_due
FROM customer c
Left join
(
  SELECT bad.basket_id as baskets
       , bad.customer_id as customer_id
       , bad.amount_due as amount_due_tot
       , sum(COALESCE(p.amount_paid, 0)) as amount_paid_tot
       , bad.amount_due - SUM(COALESCE(p.amount_paid, 0)) as amount_due_balance_tot
       , sale_status_id
  FROM basket_amount_due bad
    LEFT JOIN basket b USING (basket_id)
    LEFT JOIN basket_payment p USING (basket_id)
    LEFT JOIN customer c ON b.customer_id = c.customer_id
  WHERE b.sale_status_id = 4
  GROUP BY basket_id, sale_status_id
) d
on c.customer_id = d.customer_id
GROUP BY c.customer_id;

Answer 2

您查询的第二部分 select 是所有具有到期金额的购物篮以及客户。您希望每个客户一个结果行。那么为什么要按购物篮和销售状态分组呢？为什么要取消地址？这似乎没有多大意义。我只希望：

SELECT c.customer_id
     , c.name AS cname
     , CONCAT_WS(', ', NULLIF(c.address, ''), c.city) AS address
     , SUM(p.amount_due) AS total_sale
     , COALESCE(SUM(p.amount_paid), 0) AS total_paid
     , SUM(p.amount_due) - COALESCE(SUM(p.amount_paid), 0) AS total_due
FROM basket_amount_due bad
JOIN basket b USING (basket_id)
LEFT JOIN basket_payment p USING (basket_id)
JOIN customer c ON c.customer_id = bad.customer_id
WHERE b.sale_status_id = 4
GROUP BY c.customer_id
ORDER BY c.customer_id;

这仅显示在 basket_amount_due table 中有条目的客户。如果您想要所有客户，则来自客户和外部的 select 加入其他 tables。

此查询还假定每个篮子 basket_amount_due 中最多有一行。你的也是。如果不是这种情况，则不要将其行与 basket_payment 行连接起来，而是在连接前进行聚合。否则你会得到不正确的结果。

MySQL 中的 UNION 查询问题

UNION query issue in MySQL

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