SQL优化（DB2）:表A多字段关联表B唯一字段，查询优化

Question

SELECT
RULE_ID,
(select distinct m.GROUP_NAME from TBL_GRP m where m.GROUP_ID = n.GROUP_ID ) AS GROUP_ID,
SCORE_PARAM,
CASH_PARAM,
(select distinct m.GROUP_NAME from TBL__GRP m where m.= n.GROUP_ID2 ) AS GROUP_ID2,
SCORE_PARAM2,
CASH_PARAM2,
(select distinct m. GROUP_NAME from TBL_GRP m where m.GROUP_ID = n.GROUP_ID3 ) AS GROUP_ID3,
SCORE_PARAM3,
CASH_PARAM3,
(select distinct m.GROUP_NAME from TBL_GRP m where m.GROUP_ID = n.GROUP_ID4 ) AS GROUP_ID4,
SCORE_PARAM4,
CASH_PARAM4,
(select distinct m.GROUP_NAME from TBL_GRP m where m.GROUP_ID = n.GROUP_ID5 ) AS GROUP_ID5,
SCORE_PARAM5,
CASH_PARAM5
FROM
TBL_RULE n

Answer 1

楼主：我的建议是创建第三张表，然后在实时记录时，在第三张表中进行统计