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mysql - 连接 4 个表导致空结果

问题描述

我有 4 张桌子，每张桌子都有这个细节

熟食订单表

order_code | code | plat_create_time | status
OC001        C001   2019-04-14    Success
OC002        C002   2019-04-14    Success
OC003        C003   2019-04-14    Success

pg_order 表

id |order_code | code | plat_create_time
1    OC001       C001   2019-04-14
2    OC002       C002   2019-04-14
3    OC003       C003   2019-04-14

pg_package 表

pg_order_id | plat_create_time | cm_sign_time
1                2019-04-14         2019-04-14
2                2019-04-14         2019-04-14
3                2019-04-14             -

pg_send_package 表

order_code | code | plat_create_time | lp_sign_time
OC001        C001   2019-04-14             -
OC002        C002   2019-04-14             -
OC003        C003   2019-04-14         2019-04-14

我需要计算具有“cm_sign_time”或“lp_sign_time”的交易数据。pg_package 表需要先连接到 pg_order，然后才能连接到 deli_order 表。

首先，我尝试先将 pg_send_package 表与 deli_order 表连接起来。这是我的查询

SELECT 
    DATE(A.create_time) AS 'Create Time',
    SUM(CASE
        WHEN B.lp_sign_time IS NOT NULL THEN 1
        ELSE 0
    END) AS 'Completed Order'
FROM
    deli_order A
INNER JOIN pg_send_package B ON B.order_code = A.order_code AND B.code = A.code
WHERE DATE(A.plat_create_time) = '2019-04-14'
GROUP BY DATE(A.plat_create_time);

和结果

Create Time | Completed Order
2019-04-14     130

但是当我加入另外两张桌子时，我得到的结果什么都没有。这是我的查询

SELECT 
    DATE(A.plat_create_time) AS 'Create Time',
    SUM(CASE
        WHEN B.lp_sign_time IS NOT NULL THEN 1
        WHEN D.cm_sign_time IS NOT NULL THEN 1
        ELSE 0
    END) AS 'Completed Order'
FROM
    deli_order A
INNER JOIN pg_send_package B ON B.order_code = A.order_code AND B.code = A.code
INNER JOIN pg_order C ON C.order_code = A.order_code AND C.oms_code = A.code
INNER JOIN pg_package D ON D.pg_order_id = C.id
WHERE
    DATE(A.plat_create_time) = '2019-04-14'
GROUP BY DATE(A.plat_create_time);

这是结果

Create Time | Completed Order

我需要对具有“lp_sign_time”或“cm_sign_time”的事务的计数结果求和。

我的预期结果是

Create Time | Completed Order
2019-04-14        150

150 来自 130 笔带有“lp_sign_time”的交易和 20 笔带有“cm_sign_time”的交易 我应该在查询中更改什么？

标签： mysqlsqljoin

解决方案

您可以尝试使用UNION ALLcombinepg_send_package和 pg_packagetable 为order_code,code,lp_sign_timethen 做一个OUTER JOIN结果集COUNT。

SELECT DATE(A.plat_create_time) AS 'Create Time', 
       COUNT(lp_sign_time) AS 'Completed Order'
FROM deli_order A
LEFT JOIN
(
    SELECT order_code, 
           code, 
           lp_sign_time
    FROM pg_send_package psp
    UNION ALL
    SELECT C.order_code, 
           C.code, 
           pp.cm_sign_time
    FROM pg_package pp
         INNER JOIN pg_order C ON pp.pg_order_id = C.id
) t1 ON t1.order_code = A.order_code
        AND t1.code = A.code
        AND DATE(A.plat_create_time) = '2019-04-14'
GROUP BY DATE(A.plat_create_time);

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