sqlserver 两个表怎么关联更新

 sqlserver 

UPDATE t1
SET t1.column_to_update = t2.column_to_use
FROM Table1 t1
INNER JOIN Table2 t2 ON t1.id = t2.id
WHERE t2.some_condition = 'SomeValue'

 

 

sqlite

UPDATE tab1
  SET field1 = (SELECT tab2.field3 FROM tab2 WHERE tab2.FID = tab1.ID),
  WHERE EXISTS (SELECT * FROM tab2 WHERE tab2.FID = tab1.ID)

或

UPDATE tab1
  SET (field1, field2) = (SELECT tab2.field3, tab2.field4 FROM tab2 WHERE tab2.FID = tab1.ID)
  WHERE EXISTS (SELECT * FROM tab2 WHERE tab2.FID = tab1.ID) 

UPDATE FROM 方式

 

UPDATE tab1
   SET field1 = t.zd3
  FROM (SELECT sum(field3) AS zd3, FID FROM tab2 GROUP BY FID) AS t
  WHERE ID = t.FID;