左內連接時選擇帶分組的情況

Question

我有這段代碼返回我想要的結果；

select stktype, Part_No,
Case when stktype = 'labour' then Part_No END
from fleet_job_jobdetails
where JobCode = '176071' AND StkType = 'labour'
group by part_no, StkType

stktype Part_No（無列名）Labor ANDR ANDR

當我將其添加到較大的代碼中時，出現錯誤

LEFT JOIN (
           SELECT   jobcode
           ,        SUM(linecost) AS totalcost
           ,        SUM(CASE WHEN stktype = 'sublet' THEN linecost
                             ELSE 0
                        END) AS subletcost
           ,        SUM(CASE WHEN stktype = 'labour' THEN linecost
                             ELSE 0
                        END) AS labourcost
           ,        SUM(CASE WHEN stktype = 'part' THEN linecost
                             ELSE 0
                        END) AS partscost
           ,        SUM(CASE WHEN stktype NOT IN ('sublet', 'labour', 'part') THEN linecost
                             ELSE 0
                        END) AS othercost
        ,           **CASE WHEN (select StkType from fleet_job_jobdetails WHERE stktype = 'labour')  = 'labour' THEN Part_No  ELSE '' END AS Mech**
           FROM     fleet_job_jobdetails
           GROUP BY jobcode, Part_No
          ) a
        ON fleet_job_jobmaster.jobcode = a.jobcode

Answer 1

Part_No 僅在這種情況下

** CASE
                       WHEN (select StkType
                               from fleet_job_jobdetails
                              WHERE stktype = 'labour') = 'labour' THEN
                        Part_No

因此不會出現Part_No的情況，您必須修改該語句以確保Part_No存在，並且在WHEN THEN不存在

或者你只是只組jobcode

Answer 2

嘗試這個：

LEFT JOIN (
       SELECT   jobcode
       ,        SUM(linecost) AS totalcost
       ,        SUM(CASE WHEN stktype = 'sublet' THEN linecost
                         ELSE 0
                    END) AS subletcost
       ,        SUM(CASE WHEN stktype = 'labour' THEN linecost
                         ELSE 0
                    END) AS labourcost
       ,        SUM(CASE WHEN stktype = 'part' THEN linecost
                         ELSE 0
                    END) AS partscost
       ,        SUM(CASE WHEN stktype NOT IN ('sublet', 'labour', 'part') THEN linecost
                         ELSE 0
                    END) AS othercost
                    --Here seems subquery is not required we can simply replace with it
        ,           CASE WHEN stktype = 'labour' THEN Part_No  ELSE '' END AS Mech 
       FROM     fleet_job_jobdetails
       GROUP BY jobcode, Part_No
      ) a
    ON fleet_job_jobmaster.jobcode = a.jobcode