Question

我有这张桌子：

CREATE TABLE table1 (
id INT NOT NULL PRIMARY KEY,
value1 INT NOT NULL,
value2 INT NOT NULL
);

CREATE TABLE table2 (
    id INT NOT NULL PRIMARY KEY,
    table1_id INT NOT NULL,
    valuex INT NOT NULL
);

INSERT INTO table1 (id, value1, value2)
VALUES
    (1, 10, 15),
    (2, 5 ,  3);

INSERT INTO table2 (id, table1_id, valuex)
VALUES
    (1, 1, 15),
    (2, 1, 25),
    (3, 2, 14),
    (4, 2, 10);

有了这个：

SELECT COUNT(`table1`.`id`) AS `orders`, 
   SUM(`value1`) as `sum_value1`, SUM(`value2`) as `sum_value2`, 
   SUM(`valuex`) as `sum_valuex` 
FROM `table1` 
     INNER JOIN `table2` 
         ON `table1`.`id` = `table2`.`table1_id`

我得到了输出：

+----------------------------------------------+
+ orders | sum_value1 | sum_value2 |sum_valuex +
+----------------------------------------------+
+    4   |     30     |     36     |    64     +
+----------------------------------------------+

但我在table1中只有两个订单。我知道由于连接而重复，但是如何通过添加sum_valuex来解决这个问题呢？

我想要的结果是：

+----------------------------------------------+
+ orders | sum_value1 | sum_value2 |sum_valuex +
+----------------------------------------------+
+    2   |     15     |     18     |    64     +
+----------------------------------------------+

编辑：我不能在select

中使用select

Answer 1

这是加入工作的方式。如果您不希望在聚合之前将行相乘，则在执行join之前聚合。

SELECT t2.orders, t1.value1, t1.value2, t2.sum_valuex FROM `table1` INNER JOIN (SELECT table1_id, SUM(valuex) as sum_valuex, COUNT(*) as orders FROM table2 GROUP BY table1_id ) t2 ON t1.id = t2.table1_id

Answer 2

哪个表有订单？现在，你的count（table1.id）正在计算表2中的记录。（表2中这是该列的位置）如果Table1是包含其中订单的表，那么你应该计算表1中的记录< / p>

SELECT COUNT(distinct a.id) orders, 
    SUM(value1) as sum_value1`, SUM(value2) as sum_value2, 
    SUM(valuex) as sum_valuex 
FROM table1 a 
   JOIN table2 b 
     ON b.table1_id = a.id

Answer 3

你可以得到这样的欲望结果：

将count（订单）作为订单，SUM（t1.value1）作为value1，SUM（t1.value2）作为value2，SUM（t2.sum_valuex）作为sumvaluex FROM table1 t1 INNER JOIN （SELECT table1_id，SUM（valuex）为sum_valuex，COUNT（*）为订单从table2 GROUP BY table1_id ）t2 ON t1.id = t2.table1_id

请不要忘记标记我的答案:)

连接表使值加倍

3 个答案: