加入三張表以獲取MySQL中的摘要數據

我是SQL中的新手，並且有一個問題，我相信可以用一些SQL查詢完成...如果我更好地理解聯接。加入三張表以獲取MySQL中的摘要數據

我有三個表，每個表通過主鍵/外鍵鏈接到另一個。現實情況是，有大約60,000條記錄中最深的表，但爲了簡單起見，你可以重新創建我的表結構與此：

CREATE DATABASE IF NOT EXISTS test; 
USE test; 
CREATE TABLE IF NOT EXISTS FileData (fd_ID_pk INT NOT NULL AUTO_INCREMENT PRIMARY KEY, Analyst VARCHAR(2) NOT NULL); 
INSERT INTO FileData (Analyst) VALUES('AD'), ('LS'), ('MM'), ('MM'), ('MM'), ('LS'), ('LS'), ('AD'), ('MM'); 
CREATE TABLE IF NOT EXISTS IndData (sp_ID_pk INT NOT NULL AUTO_INCREMENT PRIMARY KEY, fd_ID_fk INT NOT NULL, IndNum INT NOT NULL, FOREIGN KEY (fd_ID_fk) REFERENCES FileData (fd_ID_pk)); 
INSERT INTO IndData (fd_ID_fk, IndNum) VALUES (1,1), (1,2), (1,3), (1,4), (1,5), (1,6), (2,1), (2,2), (2,3), (2,4), (2,5), (2,6), (2,7), (2,8), (2,9), (2,10), (3,1), (3,2), (3,3), (3,4), (3,5), (3,6), (3,7), (3,8), (3,9), (3,10), (3,11), (3,12), (3,13), (3,14), (3,15), (4,1), (4,2), (4,3), (4,4), (4,5), (4,6), (4,7), (4,8), (5,1), (5,2), (5,3), (5,4), (6,1), (6,2), (6,3), (6,4), (6,5), (6,6), (6,7), (7,1), (7,2), (7,3), (7,4), (7,5), (7,6), (7,7), (8,1), (8,2), (8,3), (8,4), (8,5), (8,6), (8,7), (8,8), (9,1), (9,2), (9,3), (9,4), (9,5); 
CREATE TABLE IF NOT EXISTS FinData (sp_1_fk INT NULL, sp_2_fk INT NULL, sp_3_fk INT NULL, FOREIGN KEY (sp_1_fk) REFERENCES IndData (sp_ID_pk), FOREIGN KEY (sp_2_fk) REFERENCES IndData (sp_ID_pk), FOREIGN KEY (sp_3_fk) REFERENCES IndData (sp_ID_pk)); 
INSERT INTO FinData (sp_1_fk, sp_2_fk, sp_3_fk) VALUES (57,null,64), (18,64,67), (null,11,35), (null,58,35), (null,null,24), (18,null,null), (null, 6,26), (34,null, 8), (null, 8,null), (59,68,28), (null, 1,17), (39,55,null), (65,58, 7), (null,null,10), (54, 6,null), (53,null,67), (27,19,41), (null,57, 5), (6,31,17),(4,64,25), (38,13,58), (55,null, 2), (66,null, 4), (10,10,null), (40,61,46), (null,null,52), (null,39,46), (null,11,32), (12,null,39), (56,44,21),(22,25,53), (37,null,null), (12,null,49), (43, null,13), (19,17,26), (46, 9,44), (null,13,null), (53,null, 6), (32,30,null)

基本上，第一臺是文件列表以及每個文件的分析師相關用它。每個分析人員可以有多個文件。

fd_ID_pk Analyst 
1   AD 
2   LS 
3   MM 
4   MM 
etc

第二個表是來自該文件的數據條目列表，每條記錄都有一個鍵。

sp_ID_pk fd_ID_fk IndNum 
1   1   1 
2   1   2 
3   1   3 
4   1   4 
5   1   5 
6   1   6 
7   2   1 
8   2   2 
etc

第三個表格對我來說很複雜。這有三列其中的每一個連接到記錄在第二表，它可以爲null

sp_1_fk sp_2_fk sp_3_fk 
12     39 
56  44  21 
22  25  53 
37      
12     49 
43     13 
19  17  26

我需要的是一個彙總表，顯示文件和IndData和FinData每個分析師的計數。

我已經得到了這個，給了我每分析師總計數，但他們似乎沒有權利在所有：

SELECT filedata.Analyst, COUNT(filedata.Analyst) as 'count' 
FROM filedata 
JOIN inddata 
ON filedata.fd_ID_pk = inddata.fd_ID_fk 
JOIN findata 
ON findata.sp_1_fk = inddata.sp_ID_pk OR findata.sp_2_fk = inddata.sp_ID_pk OR findata.sp_3_fk = inddata.sp_ID_pk 
GROUP BY filedata.Analyst

理想的，但是，我想要得到這樣的：

Analyst TotalFiles FilesUsed TotalInd IndUsed 
AD  2   2   14   10   
LS  3   3   24   16 
MM  4   4   32   24

有些疑問...任何意見將不勝感激！

來源

2016-07-01 jo phul

第一次嘗試獲得導致加盟表3和2

SELECT ID.sp_ID_pk, COUNT(*) AS VAL , COUNT(distinct IndNum) AS IDUSED 
    FROM IndData ID 
    LEFT JOIN FinData FD ON FD.sp_1_fk = ID.sp_ID_pk 
    LEFT JOIN FinData FDD ON FDD.sp_2_fk = ID.sp_ID_pk 
    LEFT JOIN FinData FDDD ON FDDD.sp_3_f k= ID.sp_ID_pk 
GROUP BY ID.sp_ID_pk; 



+----------+-----+--------+ 
    | sp_ID_pk | VAL | IDUSED | 
    +----------+-----+--------+ 
    |  1 | 1 |  1 | 
    |  2 | 1 |  1 | 
    |  3 | 1 |  1 | 
    |  4 | 1 |  1 | 
    |  5 | 1 |  1 | 
    |  6 | 2 |  1 | 
    |  7 | 1 |  1 | 
    |  8 | 1 |  1 | 
    |  9 | 1 |  1 | 
    |  10 | 1 |  1 | 
    |  11 | 2 |  1 | 
    |  12 | 2 |  1 | 
    |  13 | 2 |  1 | 
    |  14 | 1 |  1 | 
    |  15 | 1 |  1 | 
    |  16 | 1 |  1 | 
    |  17 | 2 |  1 | 
    |  18 | 2 |  1 | 
    |  19 | 1 |  1 | 
    |  20 | 1 |  1 | 
    |  21 | 1 |  1 | 
    |  22 | 1 |  1 | 
    |  23 | 1 |  1 | 
    |  24 | 1 |  1 | 
    |  25 | 1 |  1 | 
    |  26 | 2 |  1 | 
    |  27 | 1 |  1 | 
    |  28 | 1 |  1 | 
    |  29 | 1 |  1 | 
    |  30 | 1 |  1 | 
    |  31 | 1 |  1 | 
    |  32 | 1 |  1 | 
    |  33 | 1 |  1 | 
    |  34 | 1 |  1 | 
    |  35 | 2 |  1 | 
    |  36 | 1 |  1 | 
    |  37 | 1 |  1 | 
    |  38 | 1 |  1 | 
    |  39 | 1 |  1 | 
    |  40 | 1 |  1 | 
    |  41 | 1 |  1 | 
    |  42 | 1 |  1 | 
    |  43 | 1 |  1 | 
    |  44 | 1 |  1 | 
    |  45 | 1 |  1 | 
    |  46 | 2 |  1 | 
    |  47 | 1 |  1 | 
    |  48 | 1 |  1 | 
    |  49 | 1 |  1 | 
    |  50 | 1 |  1 | 
    |  51 | 1 |  1 | 
    |  52 | 1 |  1 | 
    |  53 | 2 |  1 | 
    |  54 | 1 |  1 | 
    |  55 | 1 |  1 | 
    |  56 | 1 |  1 | 
    |  57 | 1 |  1 | 
    |  58 | 2 |  1 | 
    |  59 | 1 |  1 | 
    |  60 | 1 |  1 | 
    |  61 | 1 |  1 | 
    |  62 | 1 |  1 | 
    |  63 | 1 |  1 | 
    |  64 | 2 |  1 | 
    |  65 | 1 |  1 | 
    |  66 | 1 |  1 | 
    |  67 | 2 |  1 | 
    |  68 | 1 |  1 | 
    |  69 | 1 |  1 | 
    |  70 | 1 |  1 | 
    +----------+-----+--------+ 
    70 rows in set (0.01 sec)

然後用下表

mysql> select * from FileData; 
+----------+---------+ 
| fd_ID_pk | Analyst | 
+----------+---------+ 
|  1 | AD  | 
|  2 | LS  | 
|  3 | MM  | 
|  4 | MM  | 
|  5 | MM  | 
|  6 | LS  | 
|  7 | LS  | 
|  8 | AD  | 
|  9 | MM  | 
+----------+---------+ 
9 rows in set (0.00 sec)

你會得到你想要的東西

來源

2016-07-01 16:45:38

每當多個1-TO-加入吧查詢中涉及許多關係，因此大多數聚合需要在子查詢中進行計算，以防止不同的「許多」與預聚合結果計數相乘。

來源

2016-07-01 18:05:03 Uueerdo

加入三張表以獲取MySQL中的摘要數據

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