常用sql

--

---删除重复记录
DELETE FROM tmp_a t1
WHERE t1.ROWID NOT IN (
                       SELECT MIN(t2.ROWID)
                       FROM tmp_a t2
                       GROUP BY t2.TRADEID --按照想要唯一保留的字段进行分组
                      );

 

----关联更新。注意一定要加where，否则关联不上的都为Null

UPDATE GZYC_SALEPRODUCTS_INFO_bak a 
SET a.MOBILE=(SELECT t.CORRECT_MOBILE FROM tmp_a t WHERE a.TRADEID=t.tradeid )
WHERE a.TRADEID IN (SELECT TRADEID FROM  tmp_a)