2 つの変数を日付にキャストしようとしています。
1 つ (最初のコード) をキャストするために SQL を機能させることができますが、2 つの変数をキャストしようとするとエラーが発生し続けます (以下の 2 つの試行を参照)。
キャストダブルとキャストツー変数を検索しましたが、ダブルはダブルタイプになり、変数には同じ問題があります。2 つの変数をキャストするためにどの作業を検索する必要があるか、またはどのような「結合」が必要か。
ワンキャスト(ワーキング)
cmd.CommandText = "SELECT datestart, DateEnd, runcompleted FROM [tblweeklyreports] where Cast(datestart as date) between '" & vDateStart & "' and '" & vDateStart & "'"
-2 キャスト (動作しない)
sSQL = "SELECT datestart, DateEnd, runcompleted FROM [tblweeklyreports] where Cast(moduledatestart as date, moduledatecomplete as date) between '" & vDateStart & "' and '" & vDateEnd & "'"
と
sSQL = "SELECT datestart, DateEnd, runcompleted FROM [tblweeklyreports] where Cast(moduledatestart as date),(moduledatecomplete as date) between '" & vDateStart & "' and '" & vDateEnd & "'"
それは前に出てくる必要があります(必要なのはリンクだけですが、正しい言葉遣いを探すことができないようです!)
------------------- 議論による修正版 --------------
Dim cn As SqlConnection = New SqlConnection()
Dim cmd As SqlCommand = New SqlCommand()
Dim dr As SqlDataReader
Dim vRunCompleted As String = ""
Dim vDateStartExist As String = ""
cn.ConnectionString = ConfigurationManager.ConnectionStrings("mySQLConnectionString").ConnectionString
cmd.Connection = cn
'Open the connection to the database
cn.Open()
Dim vDateStartDate As Date = vDateStart Dim vDateEndDate As Date = vDateEnd
cmd.CommandText = "SELECT * FROM [tblresults] where moduledatestart between @from and @to"
cmd.Parameters.AddWithValue("@from", vDateStart)
cmd.Parameters.AddWithValue("@to", vDateEnd)
Dim str As New StringBuilder
Dim vdrOkay As String
str.Append(Chr(34) & " Employee Id" & Chr(34) & "," & "Forename" & "," & Chr(34) & "Surname" & Chr(34) & "," & "Control 1" & "," & Chr(34) & "Control 2" & Chr(34) & "," & "Full code" & "," & "Class Name" & "," & "Year" & ",")
str.Append(Chr(34) & " Number" & Chr(34) & "," & "Class Start Date" & "," & Chr(34) & "Class End Date" & Chr(34) & "," & "Course Type" & "," & Chr(34) & "Provider Type" & Chr(34) & "," & "Provider" & "," & "Venue" & "," & "Evaluation" & "," & "Duration Hrs" & ",")
str.Replace(",", vbNewLine, str.Length - 1, 1) ' go to next line
dr = cmd.ExecuteReader()
If (dr.HasRows = True) Then
Label1.Text = "running"
While (dr.Read())
vdrOkay = Trim(StrConv(dr("EmployeeID"), VbStrConv.Uppercase))
str.Append("=" & Chr(34) & vdrOkay & Chr(34) & ",")
End While
Dim vFileName As String = Replace(vDateStart, "/", "_") & "_" & Replace(vDateEnd, "/", "_")
My.Computer.FileSystem.WriteAllText(("C:\sites\Examples\WeeklyReport\" & "ELearning_Report_" & vFileName & ".csv"), str.ToString, False)
Else
Label1.Text = "did not run"
End If