私はこのエラーをグーグルで検索しましたが、なぜこのエラーが発生するのかについて結論を出していません。DataGridViewにいくつかのデータを入力しようとしています。これが私のコードです。
Private Sub LoadGrid()
Dim cmd As New OleDbCommand
Dim dt As DataTable
With cmd
.CommandText = "project_master_query"
.CommandType = CommandType.StoredProcedure
.Connection = New OleDbConnection(My.Settings.cnnString)
End With
dt = GetData(cmd)
dgvData.DataSource = dt
End Sub
Private Function GetData(ByVal cmd As OleDbCommand) As DataTable
Dim dt As New DataTable
Using cmd.Connection
cmd.Connection.Open()
dt.Load(cmd.ExecuteReader(CommandBehavior.CloseConnection))
End Using
Return dt
End Function
Access内に保存されているクエリ「project_master_query」。
SELECT project_master.*, location_master.LocationName,
project_currentmilestonedef.MilestoneDefID,
project_currentmilestonedef.MilestoneName, project_regions.RegionName,
owner_fullname.FullName AS OwnerFullName, designer_fullname.FullName AS DesignerFullName,
project_issuecount.HasOpenIssues, project_updated_closedate.UpdatedCloseDate,
project_bonusdays.BonusDays, project_bonusdays.IsGreen, project_bonusdays.IsYellow,
project_bonusdays.IsRed, checklist_days_perproject_defined_1.Week1,
checklist_days_perproject_defined_1.Week2, checklist_days_perproject_defined_1.Week3,
checklist_days_perproject_defined_1.Week4, project_issueduration.ProjectIssueDurationDays,
project_active_status.ProjectIsOpen, project_requirement_status.RequirementStatusName,
priority_def.PriorityShortName
FROM project_requirement_status
RIGHT JOIN (project_regions
RIGHT JOIN (priority_def RIGHT JOIN (location_master
RIGHT JOIN ((((checklist_days_perproject_defined AS checklist_days_perproject_defined_1
RIGHT JOIN ((((((((contacts_fullname AS designer_fullname
RIGHT JOIN (contacts_fullname AS owner_fullname
RIGHT JOIN project_master ON owner_fullname.ContactID = project_master.ContactOwner)
ON designer_fullname.ContactID = project_master.ContactDesigner)
LEFT JOIN project_issuecount
ON project_master.ProjectID = project_issuecount.ProjectID)
LEFT JOIN project_currentmilestonedef
ON project_master.ProjectID = project_currentmilestonedef.ProjectID)
LEFT JOIN project_within_benchmark_week1
ON project_master.ProjectID = project_within_benchmark_week1.ProjectID)
LEFT JOIN project_within_benchmark_week2
ON project_master.ProjectID = project_within_benchmark_week2.ProjectID)
LEFT JOIN project_within_benchmark_week3
ON project_master.ProjectID = project_within_benchmark_week3.ProjectID)
LEFT JOIN project_updated_closedate
ON project_master.ProjectID = project_updated_closedate.ProjectID)
LEFT JOIN checklist_days_perproject_defined
ON project_master.ProjectID = checklist_days_perproject_defined.ProjectID)
ON checklist_days_perproject_defined_1.ProjectID = project_master.ProjectID)
LEFT JOIN project_issueduration
ON project_master.ProjectID = project_issueduration.ProjectID)
LEFT JOIN project_active_status
ON project_master.ProjectID = project_active_status.ProjectID)
LEFT JOIN project_bonusdays ON project_master.ProjectID = project_bonusdays.ProjectID)
ON location_master.LocationID = project_master.Location)
ON priority_def.PriorityDefID = project_master.ProjectPriority)
ON project_regions.RegionID = project_master.Region)
ON project_requirement_status.RequirementStatusID = project_master.RequirementStatus;
ご覧のとおり、クエリにはNzがまったく含まれていないため、なぜこれが発生するのかまったくわかりません。dt.Loadが呼び出されると、エラーが発生します。