常用SQL整理 - UPDATE FROM_sql update from

DECLARE @T1 TABLE(ID INT,A INT)
DECLARE @T2 TABLE(ID INT,B INT)
 
 
INSERT @T1
        ( ID, A )
VALUES  ( 1, -- ID - int
          0  -- A - int
          )
INSERT @T1
        ( ID, A )
VALUES  ( 2, -- ID - int
          2  -- A - int
          )
 
INSERT @T2
        ( ID, B )
VALUES  ( 1, -- ID - int
          111  -- A - int
          )
 
UPDATE @T1
SET A = B
FROM @T1 A,@T2 B
WHERE A.ID = B.ID
 
SELECT * FROM @T1