Sql 如何在已联接的表上执行联接？

我需要在连接表上执行连接，但我不确定如何完成。希望下面的查询能够演示我正在尝试做的事情：获取国家名称、每个国家的领导人以及每个领导人的家乡

我认为这个查询的问题是在第二次与President.homightry\u Id连接时使用了连接的表“President”。我不知道还可以尝试什么

SELECT 
  Countries.Name AS Country, 
  President.Name AS Leader,
  PresidentHomeTown.Name AS LeaderHomeTown
FROM Countries
  LEFT OUTER JOIN PoliticalFigures AS President ON Countries.President_Id = President.Id
  LEFT OUTER JOIN Cities AS PresidentHomeTown ON President.HomeTown_Id = PresidentHomeTown.Id

在VS中，我得到一个错误，“多部分标识符”President.Id“无法绑定。”

表和字段的名称是虚构的，但我需要解决一个相同的问题。我改变了名字，使事情更清楚；希望这将与更多人相关

--更新--

也许原始代码有助于：

SELECT 
    CaseComparisons.Directory AS CaseComparisonDir, 
    BaselineResult.Directory AS BaselineResultDir, 
    ComparisonResult.Directory AS ComparisonResultDir,
    Setup.FullSvnLink AS SvnLink,
    BaselineVersion.FullFilePath AS BaselineExecutableDir
FROM CaseComparisons 
    LEFT OUTER JOIN Results AS BaselineResult ON CaseComparisons.BaselineResult_Id = Baseline.Id 
    LEFT OUTER JOIN Results AS ComparisonResult ON CaseComparisons.ComparisonResult_Id = Comparison.Id
    LEFT OUTER JOIN Setups AS Setup ON Baseline.Setup_Id = Setups.Id
    LEFT OUTER JOIN BuildVersions AS BaselineVersion ON BaselineResult.Version_Id = BuildVersions.Id
WHERE 
    CaseComparisons.Status = 'Queued' OR 
    Baseline.Status = 'Queued' OR 
    Comparison.Status = 'Queued'

运行查询时出现的错误：

The multi-part identifier "Baseline.Id" could not be bound.
The multi-part identifier "Comparison.Id" could not be bound.
The multi-part identifier "Baseline.Setup_Id" could not be bound.
The multi-part identifier "Setups.Id" could not be bound.
The multi-part identifier "BuildVersions.Id" could not be bound.
The multi-part identifier "Baseline.Status" could not be bound.

---

总统表中没有Id列。仔细检查。

总统表中没有Id列。仔细检查。

您指定的别名（例如在

结果中作为比较结果）与您尝试使用的别名（例如在
比较.Id
中）之间是否不匹配。因此，改变这一点：

    LEFT OUTER JOIN Results AS ComparisonResult
                 ON CaseComparisons.ComparisonResult_Id = Comparison.Id

为此：

    LEFT OUTER JOIN Results AS ComparisonResult
                 ON CaseComparisons.ComparisonResult_Id = ComparisonResult.Id

或者这个：

    LEFT OUTER JOIN Results AS Comparison
                 ON CaseComparisons.ComparisonResult_Id = Comparison.Id

（对于所有其他联接也是如此）。
您指定的别名（例如在
结果中作为比较结果）与您尝试使用的别名（例如在
比较.Id
中）之间存在不匹配。因此，改变这一点：

    LEFT OUTER JOIN Results AS ComparisonResult
                 ON CaseComparisons.ComparisonResult_Id = Comparison.Id

为此：

    LEFT OUTER JOIN Results AS ComparisonResult
                 ON CaseComparisons.ComparisonResult_Id = ComparisonResult.Id

或者这个：

    LEFT OUTER JOIN Results AS Comparison
                 ON CaseComparisons.ComparisonResult_Id = Comparison.Id

（对于所有其他联接也是如此）。
试试这个，您的名称不同：

SELECT 
    CaseComparisons.Directory AS CaseComparisonDir, 
    BaselineResult.Directory AS BaselineResultDir, 
    ComparisonResult.Directory AS ComparisonResultDir,
    Setup.FullSvnLink AS SvnLink,
    BaselineVersion.FullFilePath AS BaselineExecutableDir
FROM CaseComparisons 
    LEFT OUTER JOIN Results AS BaselineResult ON CaseComparisons.BaselineResult_Id = BaselineResult.Id 
    LEFT OUTER JOIN Results AS ComparisonResult ON CaseComparisons.ComparisonResult_Id = ComparisonResult.Id
    LEFT OUTER JOIN Setups AS Setup ON BaselineResult.Setup_Id = Setup.Id
    LEFT OUTER JOIN BuildVersions AS BaselineVersion ON BaselineResult.Version_Id = BaselineVersion.Id
WHERE 
    CaseComparisons.Status = 'Queued' OR 
    BaselineResult.Status = 'Queued' OR 
    ComparisonResult.Status = 'Queued'

试试这个，你有不同的名字：

SELECT 
    CaseComparisons.Directory AS CaseComparisonDir, 
    BaselineResult.Directory AS BaselineResultDir, 
    ComparisonResult.Directory AS ComparisonResultDir,
    Setup.FullSvnLink AS SvnLink,
    BaselineVersion.FullFilePath AS BaselineExecutableDir
FROM CaseComparisons 
    LEFT OUTER JOIN Results AS BaselineResult ON CaseComparisons.BaselineResult_Id = BaselineResult.Id 
    LEFT OUTER JOIN Results AS ComparisonResult ON CaseComparisons.ComparisonResult_Id = ComparisonResult.Id
    LEFT OUTER JOIN Setups AS Setup ON BaselineResult.Setup_Id = Setup.Id
    LEFT OUTER JOIN BuildVersions AS BaselineVersion ON BaselineResult.Version_Id = BaselineVersion.Id
WHERE 
    CaseComparisons.Status = 'Queued' OR 
    BaselineResult.Status = 'Queued' OR 
    ComparisonResult.Status = 'Queued'

看来你走对了方向？你有什么问题？你有样本数据吗？你的查询应该运行得很好。它是否抛出错误？或者重新运行的数据不是您期望的数据？可能是的重复数据。只是想检查一下
president
表中是否有一列
id
？我的“好奇”搜索结果是：“打字”->5000+，“内存”->4002，“循环”->3919”，而“->3159，“溢出”->2670似乎你走对了方向？你有什么问题？你有样本数据吗？你的查询应该运行得很好。它是否抛出错误？或者重新运行的数据不是您期望的数据？可能是的重复数据。只是想检查一下
president
表是否有一列
id
？我的“好奇”搜索结果是：“打字”->5000+，“内存”->4002，“循环”->3919”，而“->3159，“溢出”->2670谢谢，就是这样。只是打字错误，是吗？令人尴尬的我会尽快核对答案。（剩余2分钟）谢谢，就这样。只是打字错误，是吗？令人尴尬的我会尽快核对答案。（还剩2分钟）