Question

我正在根据TechnicianName加入多个表，其中我希望将一个列值放入行中：

我有4个表easy_tbljobcard，easy_tbltechnician和easy_tblproblem以及easy_tbltechnicianMaster
我从TechnicianName的{{1}}第二列获得easy_tbltechnicianMaster technicianId
我想在查询的第3栏中easy_tbltechnician STUFF）

当前SQL语句：

p.ProblemReported

查询结果：

 SELECT j.CardID, 
      , (SELECT TechnicianName FROM easy_tbltechnicianMaster WHERE TechnicianID = t.technicianID) AS TechnicianName
      , p.ProblemReported 
 FROM easy_tbljobcard AS j 
 JOIN easy_technician AS t ON t.CardID = j.CardID  
 LEFT JOIN easy_tblproblem AS p ON p.CardID = t.CardID

上述结果应转换为：

╔══════════╦══════════════════╦═══════════════════╗
║  CardID  ║  TechnicianName  ║  ProblemReported  ║
╠══════════╬══════════════════╬═══════════════════╣
║    1     ║      AKBAR       ║     PROBLEM A     ║
║    1     ║      AKBAR       ║     PROBLEM B     ║
║    1     ║      AKBAR       ║     PROBLEM C     ║
║    1     ║      ASANKA      ║     PROBLEM A     ║
║    1     ║      ASANKA      ║     PROBLEM B     ║
║    1     ║      ASANKA      ║     PROBLEM C     ║
╚══════════╩══════════════════╩═══════════════════╝

如何在连接多个表时执行此操作？

SQLFiddle

Answer 1

您可以指定CTE – common table expression来存储您的临时结果：

with cteTbl ( CardID
            , TechName
            , problemReported ) as ( 
select j.CardID
     , p.ProblemReported
     , ( select TechnicianName
         from easy_tbltechnicianMaster
         where TechnicianID =  t.technicianID ) as TechName
from easy_tbljobcard as j 
join easy_technician as t on t.CardID = j.CardID  
left join easy_tblproblem as p  on p.CardID = t.CardID )

然后select从中t.techName并使用t.CardID将所有列值与同一行for xml path('')和,连接起来，然后替换第一个逗号{{1与stuff：

select t.CardID
     , t.TechName
     , stuff( ( select ', ' + ProblemReported
                from cteTbl
                where TechName = t.TechName
                order by ProblemReported
                for xml path('') ), 1, 1, '') AS ProblemReported
from cteTbl t
group by t.TechName
       , t.CardID

SQLFiddle

如何在连接多个表时使用GROUP BY连接字符串？

1 个答案: