vb.net - 从数据库中将数据插入到 vb.net 中的数据网格中

Question

我正在尝试从数据库中检索数据。我可以连接到数据库并检索数据，但是当我尝试将其放入数据网格时，我收到一条错误消息

索引超出范围异常未处理 ORDERDETAILS.PRODUCTID。

SQL 语句有效，但不确定将其输入数据网格的代码。任何帮助，将不胜感激。

    Dim conn As New OleDb.OleDbConnection
    conn.ConnectionString = _
    "Provider=msdaora;Data Source=orabis;User Id=112221739;Password=112221739;"

    conn.Open()


    Dim work As Integer
    work = CInt(ComboBox1.SelectedItem)

    Dim cmd As New OleDbCommand


    cmd = conn.CreateCommand()


    cmd.CommandText = "SELECT     ORDERDETAILS.PRODUCTID,PRODUCTS.PRODUCTDESCRIPTION,ORDERDETAILS.ORDERQUANTITY,ORDERDETAILS. ORDERQUANTITYTOTAL FROM CUSTOMER, ORDERS, ORDERDETAILS, PRODUCTS  WHERE CUSTOMER.CUSTOMERID = ? AND CUSTOMER.CUSTOMERID = ORDERS.CUSTOMERID AND ORDERS.ORDERID = ORDERDETAILS.ORDERID AND ORDERDETAILS.PRODUCTID = PRODUCTS.PRODUCTID"
    cmd.CommandType = CommandType.Text

    cmd.Parameters.AddWithValue("?", work)
    Dim dr As OleDb.OleDbDataReader
    dr = cmd.ExecuteReader()
    If dr.HasRows Then
          DataGridView1.Rows.Add(CInt(dr.Item("ORDERDETAILS.PRODUCTID")),        CStr(dr.Item("PRODUCTS.PRODUCTDESCRIPTION")), CInt(dr.Item("ORDERDETAILS.ORDERQUANTITY")), CInt(dr.Item("ORDERDETAILS.ORDERQUANTITYTOTAL")))
    End If
    dr.Close()
    cmd.ExecuteNonQuery()

Answer 1

在获取值之前，您需要从数据读取器中读取。

If dr.Read Then
      DataGridView1.Rows.Add(CInt(dr.Item("ORDERDETAILS.PRODUCTID")),        CStr(dr.Item("PRODUCTS.PRODUCTDESCRIPTION")), CInt(dr.Item("ORDERDETAILS.ORDERQUANTITY")), CInt(dr.Item("ORDERDETAILS.ORDERQUANTITYTOTAL")))
End If