鉴于对一个或多个参数

Question

Public Sub fillproductinfo(ByVal Productid As String) 
    ProductsTA.FillByProductID(ProductDataset.Products, Productid) 
End Sub 

If DataGridView1.SelectedRows.Count = 0 Then 
    Exit Sub 
End If 


Dim productid = DataGridView1.SelectedRows(0).Cells(0).Value 
EditProduct.fillproductinfo(productid) 


Dim EditProductwindow As New EditProduct 
If EditProduct.ShowDialog = Windows.Forms.DialogResult.OK Then 
    ProductsTableAdapter1.Fill(MyDataset.Products) 
End If 

我的数据库中的实际列名是Product ID，当我使用SQL语句我把这个条件“where ProductID = ?”

Answer 1

当问这样一个问题做了一个查询No值你会更好地显示你的SQL语句以及显示流程的代码，例如在你的例子中，你在程序/函数/事件之外有部分代码，而你应该在它们的容器中显示所述代码，例如过程/函数/事件。

下面我使用Microsoft NorthWind数据库的产品表。一个查询用于获取所有数据，另一个查询通过主键获取数据（一条记录），最后一个查询获得您似乎不需要的产品列表，但这里是完整的，因为我不希望用户输入一个无效的ID或名称，这可以称赞自动完成组合框。我已经评论了代码的每个部分，以便您可以跟随。

图片 数据集（的.xsd） https://1drv.ms/i/s!AtGAgKKpqdWjiGseXZ9FLOr1mMvZ 形式 https://1drv.ms/i/s!AtGAgKKpqdWjiGzfO22-jdRb-eAs

表单代码

Public Class Form1 
    Private Sub ProductsBindingNavigatorSaveItem_Click(sender As Object, e As EventArgs) _ 
     Handles ProductsBindingNavigatorSaveItem.Click 
     Me.Validate() 
     Me.ProductsBindingSource.EndEdit() 
     Me.TableAdapterManager.UpdateAll(Me.DemoDataSet) 
    End Sub 
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load 
     ' disable constraints as the query to get product name and id violate relational 
     ' rules in the database setup in Microsoft NorthWind database 
     Me.DemoDataSet.EnforceConstraints = False 
     ' FillByProductList is a subset of data e.g. id and name of product 
     Me.ProductsTableAdapter.FillByProductList(Me.DemoDataSet.Products) 
     ' create a list containing id and name of products for combo box 
     Dim ProdList As List(Of Product) = 
      Me.DemoDataSet.Products _ 
      .AsEnumerable _ 
      .Select(Function(row) New Product With 
       { 
        .Id = row.Field(Of Integer)("ProductId"), 
        .Name = row.Field(Of String)("ProductName")}) _ 
      .ToList 
     ' insert a select all 
     ProdList.Insert(0, New Product With {.Id = 0, .Name = "All"}) 
     cboProducts.DataSource = ProdList 
     cboProducts.DisplayMember = "Name" 
     cboProducts.ValueMember = "id" 
     ' clear so that we can set Constraints back on 
     Me.DemoDataSet.Products.Clear() 
     Me.DemoDataSet.EnforceConstraints = True 
    End Sub 

    Private Sub cmdGet_Click(sender As Object, e As EventArgs) Handles cmdGet.Click 
     Dim primaryKey As Integer = CInt(cboProducts.SelectedValue) 
     If primaryKey = 0 Then 
      Me.ProductsTableAdapter.Fill(Me.DemoDataSet.Products) 
     Else 
      Me.ProductsTableAdapter.FillByPrimaryKey(Me.DemoDataSet.Products, primaryKey) 
     End If 
    End Sub 
    ''' <summary> 
    ''' Demo to get current DataGridView primary key for use in a data operation 
    ''' </summary> 
    ''' <param name="sender"></param> 
    ''' <param name="e"></param> 
    Private Sub cmdCurrentRowKey_Click(sender As Object, e As EventArgs) Handles Button1.Click 
     If ProductsBindingSource.Current IsNot Nothing Then 
      Dim primaryKey As Integer = CInt(CType(ProductsBindingSource.Current, DataRowView).Item("ProductId")) 
      MessageBox.Show($"Current row primary key is {primaryKey}") 
     End If 
    End Sub 
End Class 
''' <summary> 
''' Class for ComboBox. 
''' Recommend this class be in it's own physical 
''' file, placed here for demo purposes only. 
''' </summary> 
Public Class Product 
    Public Property Id As Integer 
    Public Property Name As String 
End Class 

所以，你的代码可能看起来正确的（除了获得来自DataGridView的键值，而不是其他的数据源），但错误消息确实告诉你，主要关键是在网络条件中设置，所以为什么不发布您的查询或简单地回顾我发布和模仿在您的编辑版本q题目了。

当问这里的问题具体而不是缺乏含义，这表明你不认真学习如何纠正手头的问题。

这里的人都非常熟悉这些问题，我的猜测不会回答你如何解释你的问题。所以花时间编辑您的帖子。