我有两张 table 。
我需要将这两个表的每一行合并为 table3 中的一行。我成功获得了 table1 SUM 金额，但没有获得 table2。
例如。
表用户
+---------+-----------+
| user_id | user_name |
+---------+-----------+
| 001 | JOHN |
| 002 | ADAM |
+---------+-----------+
表1
+-----------+----------------+-------------------+---------------------+
| table1_id | table1_user_id | table1_amount | table1_date |
+-----------+----------------+-------------------+---------------------+
| 6 | 001 | 100 | 01/11/2014 10:55 |
| 7 | 002 | 100 | 01/11/2014 10:55 |
| 8 | 001 | 50 | 25/10/2014 10:55 |
| 9 | 001 | 100 | 23/10/2014 11:00 |
| 10 | 002 | 0 | 21/10/2014 11:00 |
+-----------+----------------+-------------------+---------------------+
表2
+-----------+----------------+----------------+--------------------+
| table2_id | table2_user_id | table2_amount | table2_date |
+-----------+----------------+----------------+--------------------+
| 1 | 001 | 100 | 15/11/2014 10:55 |
| 2 | 001 | 100 | 15/10/2014 10:55 |
| 3 | 002 | 100 | 11/10/2014 10:55 |
| 4 | 001 | 50 | 11/10/2014 10:55 |
+-----------+----------------+----------------+--------------------+
预期结果:
表3
+-----+---------+---------------+---------------+----------+---------+
| id | user_id | table1_amount | table2_amount | Year | Month |
+-----+---------+---------------+---------------+----------+---------+
| 1 | 001 | 100 | 100 | 2014 | 11 |
| 2 | 002 | 100 | 0 | 2014 | 11 |
| 3 | 001 | 150 | 150 | 2014 | 10 |
| 4 | 002 | 0 | 100 | 2014 | 10 |
+-----+---------+---------------+---------------+----------+---------+
我尝试过，但没有显示预期的结果。每行table2_amount的数量为NULL:
SQL=" INSERT INTO table3
SELECT user_id,SUM(table1_amount),t2.amount2,
YEAR(table1_date),MONTH(table1_date) FROM table1 a
LEFT JOIN
(SELECT c.table2_user_id,SUM(c.table2_amount) as amount2,c.table2_date
FROM table2 c
GROUP BY DATE_FORMAT(c.table2_date,'%Y-%m'),c.table2_user_id ASC
) t2
on t2.table2_user_id = a.table1_user_id AND t2.table2_date = a.table1_date
GROUP BY DATE_FORMAT(a.table1_date,'%Y-%m'),table1_user_id ASC ";
"
最佳答案
对于UNION来说，这是一项很好的任务
SELECT tx.uid,SUM(tx.a1),SUM(tx.a2),YEAR(tx.d),MONTH(tx.d)
FROM
(
SELECT t1.table1_user_id as uid,
t1.table1_amount as a1,
0 as a2,
t1.table1_date as d
FROM table1 t1
UNION
SELECT t2.table2_user_id as uid,
0 as a1,
t2.table2_amount as a2,
t2.table2_date as d
FROM table2 t2
) tx
GROUP BY DATE_FORMAT(d,'%Y-%m'),uid ASC
关于MYSQL 两个不同表分组的总和，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/26775974/