Question

我已经搜索了我的问题，但我找不到合适的东西。什么方法可以带来最终结果？

初始职位:(使用数据库：DB2）

使用UNION查询，例如：

SELECT 'HEAD', state, ID, Name, Country, '0'
FROM TABLE_A
WHERE state= '1'
UNION
SELECT 'POS', state, '0', '0', '0', Item
FROM TABLE_B
WHERE state= '1'

结果：

+------+-------+-----+------+---------+------+
| TYPE | STATE | ID  | Name | Country | Item |
+------+-------+-----+------+---------+------+
| HEAD | 1     | 999 | Test | PL      | 0    |
+------+-------+-----+------+---------+------+
| POS  | 1     | 0   | 0    | 0       | ABC  |
+------+-------+-----+------+---------+------+
| POS  | 1     | 0   | 0    | 0       | DEF  |
+------+-------+-----+------+---------+------+
| POS  | 1     | 0   | 0    | 0       | GHI  |
+------+-------+-----+------+---------+------+

所以＆＃34;州=＆＃39; 1＆＃39;＆＃34;是固定的

我想根据预查询给出的结果选择动态选择动态：

查询：

SELECT state
FROM TABLE_C

结果：

+-------+
| state |
+-------+
| 1     |
+-------+
| 2     |
+-------+
| 3     |
+-------+

最终结果应为：

+------+-------+-----+------+---------+------+
| TYPE | STATE | ID  | Name | Country | Item |
+------+-------+-----+------+---------+------+
| HEAD | 1     | 999 | Test | PL      | 0    |
+------+-------+-----+------+---------+------+
| POS  | 1     | 0   | 0    | 0       | ABC  |
+------+-------+-----+------+---------+------+
| POS  | 1     | 0   | 0    | 0       | DEF  |
+------+-------+-----+------+---------+------+
| POS  | 1     | 0   | 0    | 0       | GHI  |
+------+-------+-----+------+---------+------+
| HEAD | 2     | 888 | Test2| DE      | 0    |
+------+-------+-----+------+---------+------+
| POS  | 2     | 0   | 0    | 0       | XXX  |
+------+-------+-----+------+---------+------+
| POS  | 2     | 0   | 0    | 0       | YYY  |
+------+-------+-----+------+---------+------+
| POS  | 2     | 0   | 0    | 0       | GGG  |
+------+-------+-----+------+---------+------+
| HEAD | 3     | 555 | Test7| DE      | 0    |
+------+-------+-----+------+---------+------+
| POS  | 3     | 0   | 0    | 0       | TTT  |
+------+-------+-----+------+---------+------+
| POS  | 3     | 0   | 0    | 0       | SSS  |
+------+-------+-----+------+---------+------+
| POS  | 3     | 0   | 0    | 0       | AAA  |
+------+-------+-----+------+---------+------+

Answer 1

虽然你的问题不是很清楚你究竟想要什么......希望这就是你所需要的......

SELECT 'HEAD', state, ID, Name, Country, '0'
FROM TABLE_A
WHERE state in (SELECT state FROM TABLE_C)
UNION
SELECT 'POS', state, '0', '0', '0', Item
FROM TABLE_B
WHERE state in (SELECT state FROM TABLE_C)

SubSelect with Results Results（多行）

1 个答案: