Question

我在向数据库写日期时遇到了麻烦。我一直在寻找各地，看到许多相互矛盾的标准。

基本上我一直遇到类型不匹配。我确信这是我看不到的简单事。

我的代码如下。基本上，我进行查询，添加参数，并尝试运行它。名称和语音是文本，产品订购应该是数字（更具体地说是productID），日期是日期。

为什么命令运行时会出现不匹配的情况？

        Dim sqlCMD
        sqlCMD = "" + _
                       "INSERT INTO Orders " + _
                       "    ([NAME], " + _
                       "    [PhoneNumber], " + _
                       "    [ProductOrdered], " + _
                       "    [OrderDate]) " + _
                       "VALUES      ('@CustomerName', " + _
                       "    '@PhoneNumber', " + _
                       "    '@ProductOrdered', " + _
                       "    '@OrderDate'); "

        Dim connection As OleDb.OleDbConnection = New OleDb.OleDbConnection()
        connection.ConnectionString = ConnectionStringConst

        Dim command As OleDb.OleDbCommand = New OleDb.OleDbCommand(sqlCMD, connection)
        command.Parameters.Add("@CustomerName", OleDb.OleDbType.Char).Value = txtOrderCustName.Text
        command.Parameters.Add("@PhoneNumber", OleDb.OleDbType.Char).Value = txtOrderPhoneNum.Text
        command.Parameters.Add("@ProductOrdered", OleDb.OleDbType.Integer).Value = cmbOrderItem.SelectedIndex
        command.Parameters.Add("@OrderDate", OleDb.OleDbType.DBDate).Value = DateTime.Now


        Try
            connection.Open()   
            command.ExecuteNonQuery()      'Perform our query and insert into the table 
        Catch ex As Exception
            MsgBox("ERROR - Your query may not have completed" + vbNewLine + vbNewLine + _
                   "Error Message: " + ex.Message)
        Finally
            connection.Close()  
        End Try

Answer 1

数据类型不匹配的原因是参数名称周围存在单引号基本上你传递的是字符串而不是数字或日期

   sqlCMD = "" + _
                   "INSERT INTO Orders " + _
                   "    ([NAME], " + _
                   "    [PhoneNumber], " + _
                   "    [ProductOrdered], " + _
                   "    [OrderDate]) " + _
                   "VALUES      (@CustomerName, " + _
                   "    @PhoneNumber, " + _
                   "    @ProductOrdered, " + _
                   "    @OrderDate); "

这可能是您的类型不匹配的真正原因。

如何写日期从VB.net访问数据库

1 个答案: