子查询在如果不指定表的情况下默认在自己表中匹配,条件字段找不到会报无此字段,若存在会进行全表扫描
--正确 UPDATE WEB_PLY_BASE B SET B.N_AMT_VAR = (SELECT SUM(A.N_AMT_VAR) FROM WEB_PLY_CVRG A WHERE A.C_APP_NO = B.C_APP_NO) WHERE B.C_PLY_NO = '199320606022016000064'; --错误 UPDATE WEB_PLY_BASE SET N_AMT_VAR = (SELECT SUM(A.N_AMT_VAR) FROM WEB_PLY_CVRG A WHERE A.C_APP_NO = C_APP_NO) WHERE C_PLY_NO = '199320606022016000064';