Sql 使用before结果进行子选择（多行）

我已经找遍了我的问题，但没有找到合适的。 什么样的方法可以带来最终的结果

初始位置：使用的数据库：DB2

使用UNION进行查询，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: 结果:

+-------+ | state | +-------+ | 1 | +-------+ | 2 | +-------+ | 3 | +-------+ 最终结果应该是：

---

虽然从你的问题来看还不太清楚你到底想要什么。。。希望这是你需要的

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)

---

您的表_C是否与表_A有任何关系？将WHERE state='1'替换为WHERE state in SELECT state FROM TABLE_CThank you@Giorgos betgos，有时解决方案比预期的简单。 +-------+ | state | +-------+ | 1 | +-------+ | 2 | +-------+ | 3 | +-------+ +------+-------+-----+------+---------+------+ | 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 | +------+-------+-----+------+---------+------+

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)