在MySQL中连接三个表以获取摘要数据
我是SQL的新手，有一个问题，我相信通过几个SQL查询就可以解决。。。如果我能更好地理解你 我有三个表，每个表通过主键/外键相互链接。 事实上，最深的表中大约有60000条记录，但为了简单起见，您可以使用以下内容重新创建我的表结构：在MySQL中连接三个表以获取摘要数据,mysql,Mysql,我是SQL的新手，有一个问题，我相信通过几个SQL查询就可以解决。。。如果我能更好地理解你 我有三个表，每个表通过主键/外键相互链接。 事实上，最深的表中大约有60000条记录，但为了简单起见，您可以使用以下内容重新创建我的表结构： CREATE DATABASE IF NOT EXISTS test; USE test; CREATE TABLE IF NOT EXISTS FileData (fd_ID_pk INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
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)
fd_ID_pk Analyst
1 AD
2 LS
3 MM
4 MM
etc
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
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
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
Analyst TotalFiles FilesUsed TotalInd IndUsed
AD 2 2 14 10
LS 3 3 24 16
MM 4 4 32 24
带着一些疑问。。。任何建议都将不胜感激 首先尝试连接表3和表2得到结果
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)
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)
您将得到您想要的首先尝试结合表3和表2获得结果
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)
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)
当查询中涉及多个1对多关系时，您将得到您想要的结果。当查询中涉及多个1对多关系时，大多数聚合都需要在子查询中计算，以防止不同的“多”乘以预聚合的结果计数。当查询中涉及多个1对多关系时，大多数聚合都需要在子查询中计算，以防止不同的“多”与预聚合结果计数相乘