您好，stackoverflow的广阔世界，
问题：
我目前正在开发使用访问表单获取和插入数据的sql-server数据库。
在昨天之前，一切工作正常。现在的问题是，尝试运行插入查询时出现以下错误。
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：
这似乎是由于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。
如果在Microsoft SQL Server Management Studio中运行相同的查询，则可以进一步支持此功能，因此我可以INSERT和UPDATE Null值。
您可以在OLD ISSUE DETAILS下看到我当前正在使用的INSERT查询。
解决方案19/4/24下午1:35 PST：
似乎访问表链接未使用最新版本的SQL表。刷新链接后，一切正常运行
旧问题详情：
更新：19/4 / 24，10：33 AM PST：实现我忘记提供错误发生的位置。错误发生在QDF.Execute
据我所知，我没有这样做。所有可以为null的表列都是这样设置的，而且据我所知，vba内部的变量似乎已正确设置。
我提供了与此问题有关的代码，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);
这是我用来简化多次调用的功能：
'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
在这里我要调用函数：
'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 \/\/\/
运行此命令时，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
我很抱歉代码块墙。
如果有人知道为什么或可以弄清楚为什么会发生此错误，我将非常感谢。
UPDATE 4/24/19 11:10 AM PST：基于HansUp的建议，我使用RST.AddNew方法More details can be found here创建了一个备用插入方法。完成此操作后，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。
UPDATE 4/24/19 11:43 AM PST：经过更多测试之后。我发现我可以在Microsoft SQL Server Management Studio中为project_cancleddate插入和更新NULL值。
答案 0 :(得分：1)
进行更多实验后，我发现了问题所在。似乎SQL Server中的更改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。
答案 1 :(得分：0)
在“呼叫插入项目”中，未为字段projectID和CancelDate提供任何值。什么用于他们？
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
这就是我得到的
@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