merge批量更新数据

merge into T_USER_MEA_RESULT_DATA_INFO3 t1 using (select USERNUM,MEAYEARNAME,sum(WEIGHTSCORE) score from T_USER_MEA_RESULT_DATA_INFO3 t1 group by USERNUM,MEAYEARNAME) t2 on (t1.MEAYEARNAME=t2.MEAYEARNAME and t1.USERNUM=t2.USERNUM) when matched then UPDATE SET MEASCORE = t2.score 注意 update后面不跟表名直接跟set 适合两个以内的表关联的大数据量的更新