mysql - 连接 4 个表导致空结果

Question

我有 4 个表，每个表上都有这个细节

deli_order 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，我首先尝试将 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);

结果

Create Time | Completed Order
2019-04-14     130

但是当我加入另外两个表时，我得到的结果是什么都没有。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

我需要对带有“lp_sign_time”或“cm_sign_time”的交易的计数结果求和。

我的预期结果是

Create Time | Completed Order
2019-04-14        150

150 来自带有“lp_sign_time”的 130 笔交易和带有“cm_sign_time”的 20 笔交易我应该在查询中更改什么？

Answer 1

你可以尝试使用UNION ALL结合pg_send_package和pg_package表为order_code,code,lp_sign_time 然后使用 COUNT 执行 OUTER JOIN。

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);