Question

我在Sql Server中有3个表。以下是表的结构。

employee表将包含员工列表。项目表将具有项目列表。映射表将在员工与项目之间以及每个星期的小时数之间进行映射。映射表将没有针对所有员工和项目的映射。我需要加入3个表，并在一个星期内获得一个特殊项目的所有员工的结果。如果某个特殊员工本周末没有工作时间，则应提供员工详细信息，但工作时间应为0。

我有以下查询，但它仅显示映射表中具有weekEnding值的员工。

    SELECT RT.EMP_ID,RT.EMP_NAME, RT.EMP_EMAIL_ID, RPM.WEEK_ENDING, RPM.RSC_HOURS_LOGGED
 FROM vl.rsrc_prjct_hrs_mapping RPM  right outer Join vl.resource  RT ON RT.EMP_ID = RPM.EMP_ID 
 JOIN 
 vl.project PT ON PT.PROJECT_ID=RPM.PROJECT_ID WHERE PT.PROJECT_IRM='TMPT-4854' AND
  PT.PROJECT_DESC='33801-Urgent Care EnhancementEPDS V2' AND 
  RPM.WEEK_ENDING BETWEEN '2018-07-07' AND '2018-08-07';

但是我希望所有的员工都可以参加，但是应该到结局的一周，小时数应该为0。

我也尝试使用以下查询：

select RT.EMP_ID,RT.EMP_NAME, RT.EMP_EMAIL_ID,tt.week_ending,tt.RSC_HOURS_LOGGED from vl.resource  RT left outer join (select RPM.EMP_ID,RPM.WEEK_ENDING, RPM.RSC_HOURS_LOGGED from vl.rsrc_prjct_hrs_mapping RPM join vl.project PT ON PT.PROJECT_ID=RPM.PROJECT_ID WHERE PT.PROJECT_IRM='TMPT-4854' AND PT.PROJECT_DESC='33801-Urgent Care EnhancementEPDS V2' AND RPM.WEEK_ENDING BETWEEN '2018-07-07' AND '2018-07-07') tt on RT.EMP_ID = tt.EMP_ID;

但这给了employee表中的所有雇员，但是我只想要特定项目的雇员。

Answer 1

RIGHT OUTER JOIN，其中JOIN隐式转换为INNER JOIN，因此右外连接在这里没有用。更改联接的顺序或同时进行外部联接

此外，您需要将RPM.WEEK_ENDING BETWEEN '2018-07-07' AND '2018-08-07'移至ON的{{1}}子句

Right outer join

Answer 2

我不建议使用right join。这只是令人困惑。使用let join-将所有行保留在第一个表中，并将匹配的行保留在后续表中。

因此，如果要保留所有员工，则从该表开始：

SELECT RT.EMP_ID, RT.EMP_NAME, RT.EMP_EMAIL_ID, RPM.WEEK_ENDING, RPM.RSC_HOURS_LOGGED
FROM vl.resource RT LEFT JOIN
     vl.rsrc_prjct_hrs_mapping RPM 
     ON RT.EMP_ID = RPM.EMP_ID AND
        RPM.WEEK_ENDING BETWEEN '2018-07-07' AND '2018-08-07' LEFT JOIN 
     vl.project PT
     ON PT.PROJECT_ID = RPM.PROJECT_ID AND
        PT.PROJECT_IRM = 'TMPT-4854' AND
        PT.PROJECT_DESC = '33801-Urgent Care EnhancementEPDS V2' ;

对项目的过滤进入ON子句。

如果只想让曾经参加过该项目的人，则需要进行其他过滤。我认为这将满足您的要求：

SELECT RT.EMP_ID, RT.EMP_NAME, RT.EMP_EMAIL_ID, RPM.WEEK_ENDING, RPM.RSC_HOURS_LOGGED
FROM vl.resource RT LEFT JOIN
     vl.rsrc_prjct_hrs_mapping RPM 
     ON RT.EMP_ID = RPM.EMP_ID AND
        RPM.WEEK_ENDING BETWEEN '2018-07-07' AND '2018-08-07' LEFT JOIN 
     vl.project PT
     ON PT.PROJECT_ID = RPM.PROJECT_ID AND
        PT.PROJECT_IRM = 'TMPT-4854' AND
        PT.PROJECT_DESC = '33801-Urgent Care EnhancementEPDS V2'
WHERE EXISTS (SELECT 1
              FROM vl.rsrc_prjct_hrs_mapping RPM2 JOIN
                   vl.project PT2
                   ON PT2.PROJECT_ID = RPM2.PROJECT_ID AND
                      PT2.PROJECT_IRM = 'TMPT-4854' AND
                      PT2.PROJECT_DESC = '33801-Urgent Care EnhancementEPDS V2'
              WHERE RPM2.EMP_ID = RF.EMP_ID 
             );

SQL Server查询未给出正确的结果

2 个答案: