SQL合并两个表并更新引用ID

Question

我有两个表，我想加入到一个表中，并使用TypeID来区分它们。比方说，类型为A和B的表是A_Level和B_Level

A的表看起来像

级别
Level_ID说明

B的表看起来像

级别
Level_ID LEVEL_DESC

A的Level_ID从表C引用为Level_ID
B的Level_ID从表D引用为Level_ID

我正在查找将两个表合并成一个表（Level_Code）并相应地更新引用的表ID的脚本。

任何帮助，非常感谢。

Answer 1

select a.Level_Id ALevelId, b.Level_Id BLevelId, 
     case ISNULL(a.Level_Id, 0) when 0 then 'B' else 'A' end AS Type, 
     case ISNULL(a.Level_Id, 0) when 0 then b.Level_Id else a.Level_Id end AS NewLevel_Id 
INTO Dummy  
FROM a 
FULL JOIN b On (a.Level_ID = b.Level_ID); 


UPDATE c 
SET c.Level_id = Dummy.NewLevel_Id 
from Dummy, c 
WHERE c.Level_Id = Dummy.ALevelId 
AND Dummy.Type = 'A'; 

UPDATE d 
SET d.Level_id = Dummy.NewLevel_Id 
from Dummy, d 
WHERE d.Level_Id = Dummy.BLevelId 
AND Dummy.Type = 'B'; 

SELECT Dummy.NewLevel_Id, a.Level, a.LevelDesc As Description 
INTO YourNewTable 
from Dummy JOIN a ON (Dummy.ALevelId = a.Level_Id) 
Where Dummy.Type = 'A' 
UNION 
SELECT NewLevel_Id, Level, LevelDesc As Description 
from Dummy JOIN b ON (Dummy.BLevelId = b.Level_Id) 
Where Dummy.Type = 'B' 

DROP TAble Dummy;