Question

我想加入同一张表来获取一些信息。

我有人员表

PersonId, FirstName, LastName, Address

患者表

PatientId，PersonId，ResponsiblePersonId

以下是我试图获取患者名字的姓名，姓氏也是负责人名字，姓氏。对于这个我加入人员表再次获得负责人，姓氏。

但我收到了许多重复记录。

SELECT   PAT.PatientId

        ,PER.PersonNumber
        ,PER.FirstName
        ,PER.LastName
        ,RES_PER.FirstName AS ResFirstName
        ,RES_PER.LastName AS ResLastName
        ,PER.Address                

FROM        dbo.Patient AS PAT
INNER JOIN  dbo.Person AS PER
    ON  PAT.PersonId = PER.PersonId
INNER JOIN  dbo.Person AS RES_PER
    ON  PAT.ResponsiblePersonId = PER.PersonId

我如何获得患者名字，姓氏和姓名;负责人的名字，患者记录的姓氏？

Answer 1

基本上，您需要在表Person上连接两次表Patient，以便在其上获取两个相关列。

SELECT  b.FirstName Patient_FirstName, 
        b.LastName Patient_LastName,  
        b.Address Patient_Address,
        c.FirstName Responsible_Firstname, 
        c.LastName Responsible_LastName, 
        c.Address Responsible_Address
FROM    Patient a
        INNER JOIN Person b
            ON a.PersonID = b.PersonID
        INNER JOIN Person c
            ON a.ResponsiblePersonId = c.PersonID

要进一步了解联接，请访问以下链接：

Visual Representation of SQL Joins

Answer 2

您需要做的就是在SQL的最后一位用PER替换RES_PER。（即PER.PersonId变为RES_PER.PersonId）。

SELECT   PAT.PatientId
        ,PER.PersonNumber
        ,PER.FirstName
        ,PER.LastName
        ,RES_PER.FirstName AS ResFirstName
        ,RES_PER.LastName AS ResLastName
        ,PER.Address                

FROM        dbo.Patient AS PAT
INNER JOIN  dbo.Person AS PER
    ON  PAT.PersonId = PER.PersonId
INNER JOIN  dbo.Person AS RES_PER
    ON  PAT.ResponsiblePersonId = RES_PER.PersonId

JOINING Same Table提供重复信息

2 个答案: