Mysql內連接查詢

Question

我在數據庫中使用了兩個表。 第一個包含與成功和不成功付款相關的數據，而第二個表包含有關服務狀態的數據。

查詢結果應合並兩個表，並將結果列表按天分組的成功和不成功付款以及按天分組的服務狀態。

第一個表看起來像：

id | charged |    date
-----------------------------
8  |  OK     |  2011-12-03
7  |  OK     |  2011-12-03
9  |  NO     |  2011-12-03
11 |  OK     |  2011-12-04
14 |  NO     |  2011-12-04

第二個表看起來像：

id  | status |   date
--------------------------
 8  |   1    | 2011-12-03
 9  |   1    | 2011-12-03
 11 |   0    | 2011-12-04
 12 |   0    | 2011-12-04
 14 |   1    | 2011-12-04

正確的查詢結果應該是：

   date    | not_charged | charged | status_1 | status_0  
-----------------------------------------------------------
2011-12-04 |      1      |   1     |    1     |    2
2011-12-03 |      1      |   2     |    2     |    0

我嘗試過的查詢看起來像這樣：

SELECT i.date, SUM(
CASE WHEN i.charged = 'NO'
THEN 1 ELSE 0 END ) AS not_charged, SUM(
CASE WHEN i.charged = 'OK'
THEN 1 ELSE 0 END ) AS charged, SUM(
CASE WHEN s.status = '1'
THEN 1 ELSE 0 END ) AS status_1, SUM(
CASE WHEN s.status = '0' THEN 1 ELSE 0 END ) AS status_0
FROM charge i INNER JOIN status s ON s.date = i.date
GROUP BY i.date

但是我得到了錯誤的結果，看起來像這樣

   date    | not_charged | charged | status_1 | status_0
---------------------------------------------------------
2011-12-04 |     3       |    3    |    2     |    4
2011-12-03 |     2       |    4    |    6     |    0

我做錯了什么，我怎樣才能得到正確的結果？

謝謝你的所有建議。

Answer 1

這假設ID列與服務狀態和支付狀態相關...

SELECT
  COALESCE(charge.date, status.date)                       AS date,
  SUM(CASE WHEN charge.charged = 'NO' THEN 1 ELSE 0 END)   AS not_charged,
  SUM(CASE WHEN charge.charged = 'OK' THEN 1 ELSE 0 END)   AS charged,
  SUM(CASE WHEN status.status  = '0'  THEN 1 ELSE 0 END)   AS status_0,
  SUM(CASE WHEN status.status  = '1'  THEN 1 ELSE 0 END)   AS status_1
FROM
  charge
FULL OUTER JOIN
  status
    ON charge.id = status.id
GROUP BY
  COALESCE(charge.date, status.date)

注意，我要注意你要如何處理7（無狀態記錄）和12（無費用記錄）。 這當前只計算那里有什么。

或者，如果您不想按ID關聯記錄，您仍然可以按日期關聯，但您需要更改邏輯。

目前你得到這個，因為你只按日期聯系...

id | charged |    date           id  | status |   date
-----------------------------    --------------------------
8  |  OK     |  2011-12-03        8  |   1    | 2011-12-03
8  |  OK     |  2011-12-03        9  |   1    | 2011-12-03

7  |  OK     |  2011-12-03        8  |   1    | 2011-12-03
7  |  OK     |  2011-12-03        9  |   1    | 2011-12-03

9  |  NO     |  2011-12-03        8  |   1    | 2011-12-03
9  |  NO     |  2011-12-03        9  |   1    | 2011-12-03

11 |  OK     |  2011-12-04        11 |   0    | 2011-12-04
11 |  OK     |  2011-12-04        12 |   0    | 2011-12-04
11 |  OK     |  2011-12-04        14 |   1    | 2011-12-04

14 |  NO     |  2011-12-04        11 |   0    | 2011-12-04
14 |  NO     |  2011-12-04        12 |   0    | 2011-12-04
14 |  NO     |  2011-12-04        14 |   1    | 2011-12-04

相反，您需要將數據合並為每個表每個日期1，然后加入......

SELECT
  COALESCE(charge.date, status.date) AS date,
  charge.not_charged,
  charge.charged,
  status.status_0,
  status.status_1
FROM
  (
   SELECT
     date,
     SUM(CASE WHEN charged = 'NO' THEN 1 ELSE 0 END) AS not_charged,
     SUM(CASE WHEN charged = 'OK' THEN 1 ELSE 0 END) AS     charged
   FROM
     charge
   GROUP BY
     date
  )
  AS charge
FULL OUTER JOIN

  (
   SELECT
     date,
     SUM(CASE WHEN charged = '0' THEN 1 ELSE 0 END) AS status_0,
     SUM(CASE WHEN charged = '1' THEN 0 ELSE 1 END) AS status_1
   FROM
     status
   GROUP BY
     date
  )
  AS status
    ON charge.date = status.date

還有其他方法，但希望這能為您解釋一下。

Answer 2

試試這個 -

SELECT date,
  SUM(IF(charged = 'NO', 1, 0)) not_charged,
  SUM(IF(charged = 'OK', 1, 0)) charged,
  SUM(IF(status = 1, 1, 0)) status_1,
  SUM(IF(status = 0, 1, 0)) status_0
FROM (
  SELECT date, charged, NULL status FROM charge
    UNION ALL
  SELECT date, NULL charged, status FROM status
    ) t
  GROUP BY date DESC;

+------------+-------------+---------+----------+----------+
| date       | not_charged | charged | status_1 | status_0 |
+------------+-------------+---------+----------+----------+
| 2011-12-04 |           1 |       1 |        1 |        2 |
| 2011-12-03 |           1 |       2 |        2 |        0 |
+------------+-------------+---------+----------+----------+

Answer 3

我建議使用UNION ALL：

select date, 
       coalesce(sum(not_charged),0) not_charged, 
       coalesce(sum(charged),0) charged, 
       coalesce(sum(status_1),0) status_1, 
       coalesce(sum(status_0),0) status_0
from (select date,
             case charged when 'NO' then 1 end not_charged,
             case charged when 'OK' then 1 end charged,
             0 status_1,
             0 status_0
      from charge
      union all
      select date,
             0 not_charged,
             0 charged,
             case status when '1' then 1 end status_1,
             case status when '0' then 1 end status_0
      from status) sq
group by date