Question

我有一个查询，我每季度都在运行，提取有关某些医疗问题的患者访问诊所的数据。查询运行正常，但我刚被要求添加性别字段，以便我们可以按男性和女性过滤患者并查看任何结果模式。我一直用于其余患者数据的人口统计表已经有一个性别列，所以我只是将它添加到我的查询中，但是当我去运行它时，我得到一个“无效的列名称”错误而且我没有不知道为什么。

由于我只需要显示患者ID，姓名，访问位置以及现在的性别，我一直在使用子查询来获取我需要过滤患者列表所需的其他数据。这就是我所拥有的：

SELECT DISTINCT
[MedHist: Patient ID] as [Patient ID],
[Patient: First Last Name] as [Patient Name],
[Patient: Gender] as [Gender],
ServiceLocationID as [Service Location]

FROM
    (SELECT DISTINCT
    mh.[MedHist: Patient ID],
    d.[Patient: First Last Name],
    d.[Patient: Date of Birth],
    d.[Patient: Gender] as [Gender],
    d.[Patient: Age],
    a.Status,
    mh.[MedHist: Procedure Code],
    pm.Description,
    v.ServiceLocationID

    FROM MedicalHistory mh INNER JOIN Demographics d ON mh.[MedHist: Patient ID] = d.[Patient: Patient ID]
        INNER JOIN Appointment a ON a.PatientID = d.[Patient: Patient ID]
        JOIN Visit v ON v.PatientID = d.[Patient: Patient ID]
        JOIN PatientMeds pm ON pm.PatientID = d.[Patient: Patient ID]

    WHERE d.[Patient: Age] ...is in a certain range
        AND a.Status ...is a certain thing
        AND pm.Description ...involves a certain medication
        AND some other stuff

    ) Demographics

正如我所提到的，在我添加Gender字段之前，这个查询运行得很好，现在我在初始[Patient: Gender]语句的SELECT部分下面有一个红色的波形，它给了我无效列名错误。有什么想法吗？

Answer 1

您可能认为该列位于人口统计表中，但事实并非如此。

最可能的原因（在这种情况下）是拼写错误。如果我不得不猜测，在“性别”之前或之后，名称中还有其他空格。

查找列实际名称的一种方法是查看information_schema.columns：

select '|' + column_name + '|'
from information_schema.columns
where table_name = 'Demographics' and
      lower(column_name) like '%gender%';

Answer 2

如果您将FROM表命名为t1，则应根据此（dinamic）tablename命名列中的列

  SELECT DISTINCT
  [t1: Patient ID] as [Patient ID],
  [t1: First Last Name] as [Patient Name],
  [t1: Gender] as [Gender],
  [t1: ServiceLocationID as [Service Location]

  FROM
      (SELECT DISTINCT
      mh.[MedHist: Patient ID],
      d.[Patient: First Last Name],
      d.[Patient: Date of Birth],
      d.[Patient: Gender],
      d.[Patient: Age],
      a.Status,
      mh.[MedHist: Procedure Code],
      pm.Description,
      v.ServiceLocationID

      FROM MedicalHistory mh INNER JOIN Demographics d ON mh.[MedHist: Patient ID] = d.[Patient: Patient ID]
          INNER JOIN Appointment a ON a.PatientID = d.[Patient: Patient ID]
          JOIN Visit v ON v.PatientID = d.[Patient: Patient ID]
          JOIN PatientMeds pm ON pm.PatientID = d.[Patient: Patient ID]

      WHERE d.[Patient: Age] ...is in a certain range
          AND a.Status ...is a certain thing
          AND pm.Description ...involves a certain medication
          AND some other stuff

      ) t1

Answer 3

更新：我正在回答我自己的问题，因为我发现了问题。

在我的子查询中，我在d.[Patient: Gender] as [Gender]语句中有SELECT（我通常会重命名这样的列，因为这个数据库中的很多表都有如此长的标题，这使得我的列不必要地变宽丑陋）。那么当我尝试在主查询中选择相同的[Patient: Gender]字段时，系统无法找到它，因为它已在子查询中重命名。以下代码有效：

SELECT DISTINCT
    [MedHist: Patient ID] as [Patient ID],
    [Patient: First Last Name] as [Patient Name],
    Gender,
    ServiceLocationID as [Service Location]

FROM
    (SELECT DISTINCT
    mh.[MedHist: Patient ID],
    d.[Patient: First Last Name],
    d.[Patient: Date of Birth],
    d.[Patient: Gender] as [Gender],
    d.[Patient: Age],
    a.Status,
    mh.[MedHist: Procedure Code],
    .....and so on

使用子查询时出现“列名无效”错误

3 个答案: