Question

SQL 2008：我试图从具有相同字段但不同数据的两个表（TODO（T）和TODO_OPERATOR（Z））获取数据（即合并），然后在合并数据上使用2个内部联接。不知道怎么做。例如，提供的@id参数将为001。您是否先以某种方式合并选择T和Z表，然后进行INNER JOINS？

SELECT
T.*, Z.*, TT.lookup_desc todo_type_desc, TS.lookup_desc status_desc
FROM TODO T
CROSS JOIN TODO_OPERATOR Z
INNER JOIN LOOKUP TT ON T.todo_type=TT.lookup_id, Z.todo_type=TT.lookup_id
INNER JOIN LOOKUP TS ON t.status=TS.lookup_id, z.status=TS.lookup_id
WHERE id=@id

简化的表格字段为：

TODO和TODO_OPERATOR：

id，status，todo_type

LOOKUP：

lookup_id，lookup_desc

由于

Answer 1

选择

一个。*

，TT.lookup_desc todo_type_desc

，TS.lookup_desc status_desc

FROM

（从TODO中选择id，status，todo_type UNION ALL从TODO_OPERATOR中选择id，status，todo_type）A

INNER JOIN LOOKUP TT ON A.todo_type = TT.lookup_id

INEN JOIN LOOKUP TS ON A.status = TS.lookup_id

WHERE id = @ id

Answer 2

SELECT  
T.*, Z.*, TT.lookup_desc todo_type_desc, TS.lookup_desc status_desc  
FROM TODO T  
INNER JOIN TODO_OPERATOR Z  
ON Z.todo_type = T.todo_type  
AND z.status = T.status
INNER JOIN LOOKUP TT ON T.todo_type=TT.lookup_id  
INNER JOIN LOOKUP TS ON T.status=TS.lookup_id  
WHERE id=@id

我不确定这对你有帮助，你提供的信息有点小。

SQL从具有多个内部联接的2个表中进行选择

2 个答案: