访问不允许在 SQL-Server 列中插入或更新空值（访问运行时错误 3162）

Question

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问题：
我目前正在开发一个使用访问表单来获取和插入数据的 sql-server 数据库。 在昨天之前一切正常。 现在的问题是我在尝试运行插入查询时收到以下错误。

Access Runtime Error '3162': You tried to assign the Null value to a variable that is not a Variant data type.

问题详情：
这似乎是 Access 不允许我在允许空值的 SQL 表列中插入或更新空值的结果。
如果我在 Microsoft SQL Server Management Studio 中运行相同的查询，则进一步支持这一点，我能够插入和更新 Null 值。
您可以在 OLD ISSUE DETAILS 下看到我当前使用的 INSERT 查询。

解决方案 2019/4/24 太平洋标准时间下午 1:35：
似乎访问表链接没有使用最新版本的 SQL 表。 刷新链接后，一切正常

---

旧问题详情：
更新：19 年 4 月 24 日，太平洋标准时间上午 10:33：意识到我忘记提供错误发生的位置。 在该InsertProject功能出现错误QDF.Execute

就我所见，我没有这样做。 所有可以为空的表列都设置为这样，并且从我所看到的，vba 中的变量似乎设置正确。

我已经提供了与此问题相关的代码、查询和其他信息。

这是我正在使用的查询：

    INSERT INTO ci_project 
    (project_id, 
    project_group, 
    project_projecttype, 
    project_hasmilestones, 
    project_hasgantt, 
    project_category, 
    project_difficulty, 
    project_notes, 
    project_completiondetails, 
    project_statuscode, 
    project_inprogressdate, 
    project_completeddate, 
    project_datecreated, 
    project_lastupdated, 
    project_canceleddate, 
    project_isActive) 
    VALUES (@projectID
    ,@projectGroup
    ,@projectType
    ,@projectHasMilestones
    ,@projectHasGantt
    ,@projectCategory
    ,@projectDifficulty
    ,@projectNotes
    ,@projectCompletionDetails
    ,@projectStatus
    ,@projectDateInProgress
    ,@projectDateComplete
    ,@projectDateCreated
    ,@projectDateUpdated
    ,@projectCanceledDate
    ,@projectIsActive);

这是我制作的函数，可以更轻松地多次调用它：

    'This is located in another Module called OtherFunctions
    Dim dbs as DAO.Database

    Public Function InsertProject(projectID As String, _
                                  projectGroup As Integer, _
                                  projectType As Integer, _
                                  projectHasMilestones As Boolean, _
                                  projectHasGantt As Boolean, _
                                  projectCategory As Integer, _
                                  projectDifficulty As Integer, _
                                  projectNotes As Variant, _
                                  projectCompletionDetails As Variant, _
                                  projectStatus As Integer, _
                                  projectDateInProgress As Variant, _
                                  projectDateComplete As Variant, _
                                  projectCanceledDate As Variant, _
                                  projectIsActive As Integer)

        OtherFunctions.Initialize

        Dim QDF As DAO.QueryDef

        If FindQuery("InsertProject") = True Then OtherFunctions.dbs.QueryDefs.Delete "InsertProject"

        Set QDF = OtherFunctions.dbs.CreateQueryDef("InsertProject", SQLInsertProject)

        QDF.Parameters("@projectID").Value = projectID
        QDF.Parameters("@projectGroup").Value = projectGroup
        QDF.Parameters("@projectType").Value = projectType
        QDF.Parameters("@projectHasMilestones").Value = projectHasMilestones
        QDF.Parameters("@projectHasGantt").Value = projectHasGantt
        QDF.Parameters("@projectCategory").Value = projectCategory
        QDF.Parameters("@projectDifficulty").Value = projectDifficulty
        QDF.Parameters("@projectNotes").Value = projectNotes
        QDF.Parameters("@projectCompletionDetails").Value = projectCompletionDetails
        QDF.Parameters("@projectStatus").Value = projectStatus
        QDF.Parameters("@projectDateInProgress").Value = ConvertDateToUnix(projectDateInProgress)
        QDF.Parameters("@projectDateComplete").Value = ConvertDateToUnix(projectDateComplete)
        QDF.Parameters("@projectDateCreated").Value = ConvertDateToUnix(Now())
        QDF.Parameters("@projectDateUpdated").Value = ConvertDateToUnix(Now())
        QDF.Parameters("@projectIsActive").Value = projectIsActive
        QDF.Parameters("@projectCanceledDate").Value = ConvertDateToUnix(projectCanceledDate)

        QDF.Execute

        If FindQuery("InsertProject") = True Then OtherFunctions.dbs.QueryDefs.Delete "InsertProject"

        Set QDF = Nothing

    End Function

这是我调用函数的地方：

    'These are set in the same sub as the insert project call
    Dim projectID As String
    Dim CancelDate As Variant
    Dim canceledStatus As Integer

    'These are located in a different module called OtherFunctions
    Public IDEASUGGESTION_HASGANT As Boolean
    Public IDEASUGGESTION_HASMILESTONES As Boolean
    Public IDEASUGGESTION_PROJECTTYPE As Integer


    ' /\/\/\ THERE IS CODE ABOVE THIS /\/\/\
        canceledStatus = 12
    If Me.IdeaStatus = canceledStatus And DatabaseQueries.CheckIdeaSuggestion(Me.IdeaID) = True Then
       CancelDate = Now()
       If MsgBox("Are you sure you want to do this? Canceling a idea will make it un-editable.", vbYesNo) = vbYes Then
           GoTo IdeaCancel
       Else
           GoTo GotoEnd
       End If
    ElseIf Me.IdeaStatus = canceledStatus And DatabaseQueries.CheckIdeaSuggestion(Me.IdeaID) = False Then
       MsgBox "You cannot cancel an idea that does not exist.", vbExclamation
       CancelDate = Null
       GoTo GotoEnd
    Else
       'other code run here not pertaining to the insert
    End If

    Call DatabaseQueries.InsertProject(
         projectID, _
         Me.IdeaGroup, _
         OtherFunctions.IDEASUGGESTION_PROJECTTYPE, _
         OtherFunctions.IDEASUGGESTION_HASMILESTONES, _
         OtherFunctions.IDEASUGGESTION_HASGANT, _
         Me.IdeaCategory, _
         Me.IdeaDifficulty, _
         Null, _
         Null, _
         Me.IdeaStatus, _
         Me.IdeaInprogressDate, _
         Me.IdeaCompleteDate, _
         CancelDate, _
         1)

    ' \/\/\/ THERE IS CODE BELOW THIS \/\/\/

当我运行它时，这些是表单值：

    Me.ideaID = Null
    Me.IdeaGroup = 1
    Me.IdeaCategory = 2
    Me.IdeaDifficulty = 1
    Me.IdeaStatus = 1
    Me.IdeaInprogressDate = Null
    Me.IdeaCompleteDate = Null
    OtherFunctions.IDEASUGGESTION_PROJECTTYPE = 1
    OtherFunctions.IDEASUGGESTION_HASMILESTONES = False
    OtherFunctions.IDEASUGGESTION_HASGANT = False

表结构为：

    Column Name                 Data Type   Can be Null
    project_id                  varchar(45) No
    project_group               int         No
    project_projecttype         int         No
    project_hasmilestones       bit         No
    project_hasgantt            bit         No
    project_category            int         No
    project_difficulty          int         No
    project_notes               text        Yes
    project_completiondetails   text        Yes
    project_statuscode          int         No
    project_inprogressdate      bigint      Yes
    project_completeddate       bigint      Yes
    project_datecreated         bigint      No
    project_lastupdated         bigint      No
    project_canceleddate        bigint      Yes
    project_isActive            int         No

我为代码块墙道歉。

如果有人知道为什么或可以弄清楚为什么会发生此错误，我将不胜感激。

更新 4/24/19 太平洋标准时间上午 11:10：根据 HansUp 的推荐，我创建了一个使用 RST.AddNew 方法的替代插入方法更多详细信息可以在这里找到。 这样做后，我发现导致悲伤的变量是 InsertProject 函数中的 projectCanceledDate。 唯一的问题是我不知道为什么，该变量被定义为 Variant。

太平洋标准时间 4/24/19 上午 11:43 更新：在进行更多测试之后。 我发现我可以在 Microsoft SQL Server Management Studio 中插入和更新 project_cancleddate 的 NULL 值。

Answer 1

在做了一些更多的实验后，我发现了问题。 似乎 SQL 服务器中的更改尚未反映在访问数据库中（即使project_canceleddate接受空值）。 刷新ci_project表上的链接后，一切正常。

Answer 2

在调用 InsertProject 中，字段 projectID 和 CancelDate 未指定任何值。 他们有什么用？

添加此简单代码以查看参数中的内容。

Dim parm As DAO.Parameter
For Each parm In QDF.Parameters
    Debug.Print parm.Name, parm.Value
Next parm

这是我得到的

  @projectID                  MyProjId
  @projectGroup               1
  @projectType                1
  @projectHasMilestones       0
  @projectHasGantt            0
  @projectCategory            2
  @projectDifficulty          1
  @projectNotes               Null
  @projectCompletionDetails   Null
  @projectStatus              1
  @projectDateInProgress      Null
  @projectDateComplete        Null
  @projectDateCreated         1556103601
  @projectDateUpdated         1556103601
  @projectCanceledDate        Null
  @projectIsActive            1