Rextester

Question

我有3张桌子a，b和c。表a包含商店的ID，其收入日期和销售数量（机票）。

表b包含服装订单的ID，销售日期和计数。

表c包含id，日期和总计数。

SQL> select * from a;

STOREID          EARNINGDATE COUNT_FLIGHT_TICKETS
-------------------- ----------- ----------------
store01         14980000           10
store01         14980001           32
store02         14980000          134

SQL> select * from b;

STOREID          EARNINGDATE CLOTHES_SALE_COUNT
-------------------- ----------- ---------------
store01         14980000           6
store02         14980000           6

SQL> select * from c;

STOREID          EARNINGDATE TOTAL_SALE_COUNT
-------------------- ----------- -------------
store01         14980001        32
store01         14980000        16
store02         14980000       134

鉴于上述表格，我必须打印所有商店ID，以及他们的总销售日期，航班销售和服装销售。

|StoreId | EarningDate | FlightCount | ClothingCount | TotalCount |

我使用了以下查询，但未能获得上述内容。

select b.storeId , sum(a.COUNT_FLIGHT_TICKETS), 
  sum(b.CLOTHES_SALE_COUNT), sum (c.TOTAL_SALE_COUNT) 
from a 
full outer join b on a.storeId = b.storeId 
  and a.EarningDate = b.earningdate 
full outer join c on a.storeId = c.storeId 
  and a.earningDate = b.earningDate group by a.storeId;

此查询不会提供所有行并且有一些错误。

STOREID          flight clothing        total
------       --------- --------- --------------------
store02           134        6           134
store01           52             12           48

有人可以帮我纠正此查询以获得预期的输出吗？

Answer 1

一种选择是获取thee表的UNION然后按商店聚合：

SELECT
    t.STOREID,
    t.EARNINGDATE,
    SUM(t.COUNT_FLIGHT_TICKETS) AS FlightCount,
    SUM(t.CLOTHES_SALE_COUNT)   AS ClothingCount,
    SUM(t.TOTAL_SALE_COUNT)     AS TotalCount
FROM
(
    SELECT
        STOREID,
        EARNINGDATE,
        COUNT_FLIGHT_TICKETS,
        0 AS CLOTHES_SALE_COUNT,
        0 AS TOTAL_SALE_COUNT
    FROM a
    UNION ALL
    SELECT STOREID, EARNINGDATE, 0, CLOTHES_SALE_COUNT, 0
    FROM b
    UNION ALL
    SELECT STOREID, EARNINGDATE, 0, 0, TOTAL_SALE_COUNT
    FROM c
) t
GROUP BY
    t.STOREID,
    t.EARNINGDATE

这解决了您正确指出的连接问题，这可能需要完全外连接。 MySQL中的完全外部联接是一件麻烦事，无论如何通常不需要设计良好。

在这里演示：

Rextester

Answer 2

假设对于每个表，（storeId，earningdate）是唯一的或复合键，group by将是不必要的。您可以尝试此查询。

select 
    IF(isnull(a.STOREID), IF(isnull(b.STOREID), c.STOREID, b.STOREID),a.STOREID) as StoreId,
    IF(isnull(a.EARNINGDATE), IF(isnull(b.EARNINGDATE), c.EARNINGDATE, b.EARNINGDATE),a.EARNINGDATE) as EarningDate, 
    IF(isnull(COUNT_FLIGHT_TICKETS),0,COUNT_FLIGHT_TICKETS) as FlightCount, 
    IF(isnull(CLOTHES_SALE_COUNT),0,CLOTHES_SALE_COUNT) as ClothingCount, 
    IF(isnull(TOTAL_SALE_COUNT),0,TOTAL_SALE_COUNT) as TotalCount  
from a full outer join b 
    on a.storeId = b.storeId and a.EarningDate = b.earningdate
    full outer join c 
       on a.storeId = c.storeId and a.earningDate = c.earningDate;

结果是：

STOREID   EarningDate    flight    clothing        total
------   -------------  --------- --------- --------------------
store01      14980000      10         6             16
store02      14980000      134        6             134
store01      14980001      32         0             32

这是您的预期结果吗？我想你忘记了收入日期。

鉴于上述表格，我必须打印所有商店ID   总销售，航班销售和服装销售的赚取日期。

| StoreId | EarningDate | FlightCount | ClothingCount | TotalCount |

完整外连接的SQL查询

2 个答案:

Rextester