SQLite 多表关联更新

SQLite 多表关联更新

更新多字段

UPDATE tab1
  SET field1 = field1 || '-',
      field2 = field2 + 1
  WHERE ID < 10

或

UPDATE tab1
  SET (field1, field2) = (field1 || '-', field2 + 1)
  WHERE ID < 10

关联更新

普通方式

 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;

参考文档

UPDATE