Vb.net消息:没有为一个或多个必需的参数给定值

Question

我做了一个POS项目，但当我保存数据访问数据库时，错误显示:

没有给出一个或多个必需参数的值。

我的代码是:

Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
    Dim MyConnection As OleDb.OleDbConnection = Nothing
    Dim MyTransaction As OleDb.OleDbTransaction = Nothing
    Try
        'create the connection and transaction object
        MyConnection = New OleDb.OleDbConnection(My.Settings.dbConnectionString)
        MyConnection.Open()
        MyTransaction = MyConnection.BeginTransaction
        'insert the new recipt
        Dim SQL As String = "insert into recipts (ReciptDate, ReciptTotal) values (:0,:1)"
        Dim CMD1 As New OleDb.OleDbCommand
        CMD1.Connection = MyConnection
        CMD1.Transaction = MyTransaction
        CMD1.CommandText = SQL
        CMD1.Parameters.AddWithValue(":0", Now.Date)
        CMD1.Parameters.AddWithValue(":1", TextBox4.Text)
        CMD1.ExecuteNonQuery()
        CMD1.Dispose()
        'get the id for the recipt
        SQL = "Select max (reciptId) as MAXID from recipts"
        Dim CMD2 As New OleDb.OleDbCommand
        CMD2.Connection = MyConnection
        CMD2.Transaction = MyTransaction
        CMD2.CommandText = SQL
        Dim ReciptID As Long = CMD2.ExecuteScalar()
        CMD2.Dispose()

        'insert the details of the recipt
        Dim I As Integer
        For I = 0 To DGV2.Rows.Count - 1
            'get the values
            Dim Barcode As String = DGV2.Rows(I).Cells(0).Value
            Dim BuyPrice As Decimal = DGV2.Rows(I).Cells(2).Value
            Dim SellPrice As Decimal = DGV2.Rows(I).Cells(3).Value
            Dim ItemCount As Integer = DGV2.Rows(I).Cells(4).Value
            'next create a command
            Dim CMD3 As New OleDb.OleDbCommand
            SQL = "insert into ReciptDetails" & _
                "(ReciptId, Barcode,ItemCount,ItemBuyPrice,ItemSellPrice)" & _
                "Values" & _
                "(:0              ,:1              ,:2         ,:3                ,:4)"
            CMD3.Connection = MyConnection
            CMD3.Transaction = Mytransaction
            CMD3.CommandText = SQL
            CMD1.Parameters.AddWithValue(":0", ReciptID)
            CMD1.Parameters.AddWithValue(":1", Barcode)
            CMD1.Parameters.AddWithValue(":2", ItemCount)
            CMD1.Parameters.AddWithValue(":3", BuyPrice)
            CMD1.Parameters.AddWithValue(":4", SellPrice)
            CMD3.ExecuteNonQuery()
            CMD3.Dispose()
        Next
        'all well save the changes
        Mytransaction.Commit()
        'close conncetion
        Mytransaction.Dispose()
        MyConnection.Close()
        MyConnection.Dispose()
        DGV2.Rows.Clear()
        TextBox4.Text = ""
    Catch ex As Exception
        If Mytransaction IsNot Nothing Then
            Mytransaction.Rollback()
        End If
        If MyConnection IsNot Nothing Then
            If MyConnection.State = ConnectionState.Open Then
                MyConnection.Close()
            End If
        End If
            MsgBox(ex.Message, MsgBoxStyle.Critical Or MsgBoxStyle.OkOnly)
    End Try
End Sub

这里有什么问题?

Answer 1

简单的排版错误。在CMD3中你将所有参数添加到CMD1

因此CMD3缺少5个参数