Question

这是我试图执行的SQL查询：

SELECT
    VisitID,
    VisitDate,
    IssuedBy,
    VisitPurpose,
    CompanyName,
    SPname as 'SalePerson',
    [1] as 'Person 1',
    [2] as 'Person 2',
    [3] as 'Person 3'
FROM (
        SELECT
            TD.VisitID,
            TD.VisitDate,
            TD.IssuedBy,
            TD.VisitPurpose,
            TC.CompanyName,
            SP.SPname,
            ROW_NUMBER() OVER(PARTITION BY TD.VisitID ORDER BY TE.AlongwithID) AS EngineerNo,
            EN.[AlongwithName]
        FROM
            tblVisitTicket AS TD
            INNER JOIN tblVisit_Alongwith AS TE
                ON TD.VisitID = TE.VisitID
            INNER JOIN tblAlongWith AS EN
                ON TE.AlongwithID = EN.AlongwithID
            INNER JOIN tblCompany AS TC
                ON TD.CompanyID = TC.CompanyID
            INNER JOIN tblSalePerson AS SP
                ON TD.SalePersonID = SP.SalePersonID
        WHERE TD.VisitStatus = 1
    ) AS DT
    PIVOT(MAX([AlongwithName])
        FOR [EngineerNo]
        IN([1], [2], [3])
    ) AS PT

现在这完全正常工作但是由于我的应用程序的设计，人员1,2和3中有时会有值，有时只有1和2有价值，有时仅有1有时会有价值其中任何一个都有价值。

现在的问题是，如果Person 1，Person 2和Person 3在所有这些中都为空，则查询会跳过整行。这是为什么？即使结果为空，我如何显示结果。

Answer 1

据我所知，您已在 tblVisitTicket 和 tblVisit_AlongWith 表之间进行了内部联接。虽然tblvisit_Alongwith可能没有特定访问的数据。

如果我是对的，那么你可以通过在这些表中使用外连接来解决问题，这样tblVisitTicket的所有数据都将可用，并且tblVisit_AlongWith的匹配数据将在那里。

SQL查询不显示为null的行

1 个答案: