mysql - SQL使用不同的返回重复记录

Question

我正在尝试执行以下查询。我期望不会出现任何重复。但是在结果集中，我得到了重复记录。我是sql新手。

SELECT DISTINCT pr.id as ruleid, pr.alias as rulename,grp.id as groupId, grp.alias, fgp.filterGroupType FROM  ProcessingService s    INNER JOIN s.fileGroupingParameter fgp ON fgp.status =:fileGroupStatus INNER JOIN s.svcPathList path ON path.status =:pathStatus  INNER JOIN path.policy p  ON p.status =:policyStatus  INNER JOIN p.policyGroupRelSet pgr  INNER JOIN pgr.group grp ON grp.status =:groupStatus  INNER JOIN grp.policyGroupRuleRelSet rr  INNER JOIN rr.policyRule pr  ON pr.status =:ruleStatus  INNER JOIN pr.policyActionSet pa ON pa.status =:actionStatus WHERE s.id in (:idList) AND pa.action =:actionType AND s.status =:serviceStatus AND fgp.filterGroupType ='Rulewise' AND pr.category =:reasonCategory AND pr.severity =:reasonSeverity

我如何根据我的要求获得不同的记录。

我得到的结果集是

"policy rule1"   
"policy rule1"  
"policy rule12"  
"policy rule12"

而且我要：

"policy rule1"  
"policy rule12" 

作为输出。

Answer 1

唯一列适用于整个列集，而不仅仅是一个。如果其中一列中有重复项，则意味着该集中的其他某列中具有唯一值。您必须决定是否需要这些唯一值。
比起您将不得不删除不需要的列或根据某种逻辑选择所需的行。