在INNER联接上使用CASE语句进行更新

Question

我有两张桌子

1.Project_Cust_Packages__c

---

Project_Id__c | LOV_Name__c |

---

101       |  PAS        |
101       |  PMS        | 
101       |  FTR        |

---

2.AAProj_Tbl

---

 ID | ISPAS |ISPMS |ISFTR |

---

101 |  NULL | NULL | NULL |

---

AND我的查询是......

    UPDATE AAProj_Tbl 

SET ISPAS=
CASE 
WHEN A.[LOV_Name__c]='PAS' THEN 'Y'
WHEN ISPAS='Y' THEN 'Y'
ELSE 'N'
END

,ISPMS=
CASE 
WHEN A.[LOV_Name__c]='PMS' THEN 'Y'
WHEN ISPMS='Y' THEN 'Y'
ELSE 'N'
END

,ISFTR=
CASE 
WHEN A.[LOV_Name__c]='FTR' THEN 'Y'
WHEN ISFTR='Y' THEN 'Y'
ELSE 'N'
END 

FROM [Project_Cust_Packages__c] A inner join AAProj_Tbl B
on B.ID=A.[Project_Id__c]

---

结果是

AAProj_Tbl

---

 ID | ISPAS |ISPMS |ISFTR |

---

101 |   N   |  N   | Y    |

---

但结果应为

---

 ID | ISPAS |ISPMS |ISFTR |

---

101 |   Y   |  Y   | Y    |

---

所有列中的Y，Y，Y因为： Project_Cust_Package_c表有包含FTR，PMS，FTR ......的项目。

Answer 1

在构建这样的查询时（即从多行更新单行中的多个列），您需要确保将两个表转换为一对一关系。这样做的一种方法是转动表A，如下所示：

UPDATE AAProj_Tbl 

SET ISPAS=
CASE 
WHEN A.[PAS] > 0 THEN 'Y'
ELSE 'N'
END

,ISPMS=
CASE 
WHEN A.[PMS] > 0 THEN 'Y'
ELSE 'N'
END

,ISFTR=
CASE 
WHEN A.[FTR] > 0 THEN 'Y'
ELSE 'N'
END 

FROM 
(SELECT [Project_Id__c], 
SUM(CASE WHEN [LOV_Name__c] = 'PAS' THEN 1 ELSE 0 END) AS [PAS],
SUM(CASE WHEN [LOV_Name__c] = 'PMS' THEN 1 ELSE 0 END) AS [PMS],
SUM(CASE WHEN [LOV_Name__c] = 'FTR' THEN 1 ELSE 0 END) AS [FTR],
FROM [Project_Cust_Packages__c] GROUP BY [Project_Id__c]) AS A
inner join AAProj_Tbl B
on B.ID=A.[Project_Id__c]