Visual Studio: 当数据库结构发生变化时重新加载数据集和数据网格

Question

我是新手，我正在尝试使用 Visual Studio 2013 在 .vb 中创建一个应用程序此应用程序可与 SQl SERVER EXPRESS 女士制作的本地数据库（我拥有的书籍、Cd、Dvd 等）配合使用，我想知道我是否可以找到一种方法通过该应用程序重新加载我的 DatagridView 和我的数据集当我使用应用程序向我的数据库添加一列时。事实上，我正试图找到一种方法在我的数据网格视图中显示这个新列，我不想总是在 VS 中，因为我想在小型笔记本电脑上使用我的应用程序。

好吧，我不知道从哪里开始，所以我尝试了这个：

Imports System.Data.SqlClient
...
Private Sub Form8_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    Dim cn As New SqlConnection("Data Source=PC-ME\SQLEXPRESS;Initial Catalog=Database;Integrated Security=True")
    Dim cmd As SqlCommand = cn.CreateCommand()
    cmd.CommandText = "Select * FROM CONSULTE"
    Dim adapter As New SqlDataAdapter()
    Dim ds As New DataSet()
    adapter.SelectCommand = cmd
    cn.Open()
    adapter.Fill(ds, "CONSULTE")
    cn.Close()
    CONSULTEDataGridView.DataSource = ds
    CONSULTEDataGridView.DataMember = "CONSULTE"

End Sub

但是没用。

我的 windows 表单，我可以在其中更改 TABLE:

Imports System.Data.SqlClient
Public Class Form7
Dim cn As New SqlConnection("Data Source=PC-ME\SQLEXPRESS;Initial Catalog=Database;Integrated Security=True")
Dim cmd As New SqlCommand
Dim dr As SqlDataReader

Private Sub Form7_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    cmd.Connection = cn
End Sub

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    If table.Text <> "" And colonne.Text <> "" And typede.Text <> "" Then
        cn.Open()
        cmd.CommandText = "ALTER TABLE " & table.Text & " ADD " & colonne.Text & " " & typede.Text & ""
        cmd.ExecuteNonQuery()
        cn.Close()
        table.Text = ""
        colonne.Text = ""
        typede.Text = ""
    Else
        MsgBox("Vous devez remplir les trois champs!")
    End If
End Sub

Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
    If table.Text <> "" And colonne.Text <> "" Then
        cn.Open()
        cmd.CommandText = "ALTER TABLE " & table.Text & " DROP COLUMN " & colonne.Text & ""
        cmd.ExecuteNonQuery()
        cn.Close()
        table.Text = ""
        colonne.Text = ""
    Else
        MsgBox("Vous devez remplir correctement les deux premiers champs!")
    End If
End Sub
End Class

感谢您的帮助！

PS:对不起我的英语，不是我的母语

Answer 1

我不是专业人士，但想尝试一下。我使用了 WithEvents 语句。

请尝试以下代码。我假设，您正在以两种形式编写代码，对吗？ Form7 和 Form 8

在表格 7 中，执行此操作

Imports System.Data.SqlClient
Public Class Form7
 ...
 Public Event LoadDataGridView(sender As System.Object)

Private Sub Form7_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    cmd.Connection = cn
End Sub

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    If table.Text <> "" And colonne.Text <> "" And typede.Text <> "" Then
      --- Your stuff here. After completion of code, following event will be raised

      RaiseEvent LoadDataGridView(sender)
    Else
        MsgBox("Vous devez remplir les trois champs!")
    End If
End Sub

Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
    If table.Text <> "" And colonne.Text <> "" Then
      -- Your stuff here. After completion of code, following event will be raised


      RaiseEvent LoadDataGridView(sender)
    Else
        MsgBox("Vous devez remplir correctement les deux premiers champs!")
    End If
End Sub
End Class

现在，在表格 8 中，执行此操作

Imports System.Data.SqlClient
Public Class Form8
Private WithEvents form7 As New Form7

Private Sub Form8_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    -- You stuff
End Sub

Private Sub form7_LoadDataGridView(sender As Object) Handles form7.LoadDataGridView
 'Call load procedure to reload datagridview
 Form8_Load(Nothing,Nothing)
End Sub
End Class

Answer 2

所以我找到了一个方法！如果有人想知道，这里有一个例子： Datagridview1 是我在 form1

上的 datagridview 的名称

表格 1：

Imports System.Data.SqlClient
Public Class Form1

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    Dim cn As New SqlConnection("Data Source=PC-ME\SQLEXPRESS;Initial Catalog=BDD;Integrated Security=True")
    cn.Open()
    Dim cmd As SqlCommand = cn.CreateCommand()
    Dim adapter As New SqlDataAdapter()
    Dim ds As New DataSet()
    Dim sql As String

    sql = "SELECT * FROM CONSULTE"
    adapter.SelectCommand = New SqlCommand(sql, cn)
    adapter.Fill(ds)
    DataGridView1.DataSource = ds.Tables(0)

End Sub
End Class

表格 3，我可以在其中添加或删除列：

Imports System.Data.SqlClient
Public Class Form3
Dim cn As New SqlConnection("Data Source=PC-ME\SQLEXPRESS;Initial Catalog=BDD;Integrated Security=True")
Dim cmd As New SqlCommand
Dim dr As SqlDataReader

Private Sub Form3_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    cmd.Connection = cn
End Sub

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    If table.Text <> "" And colonne.Text <> "" And typede.Text <> "" Then
        cn.Open()
        cmd.CommandText = "ALTER TABLE " & table.Text & " ADD " & colonne.Text & " " & typede.Text & ""
        cmd.ExecuteNonQuery()
        cn.Close()
        table.Text = ""
        colonne.Text = ""
        typede.Text = ""
    Else
        MsgBox("Vous devez remplir les trois champs!")
    End If
End Sub

Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
    If table.Text <> "" And colonne.Text <> "" Then
        cn.Open()
        cmd.CommandText = "ALTER TABLE " & table.Text & " DROP COLUMN " & colonne.Text & ""
        cmd.ExecuteNonQuery()
        cn.Close()
        table.Text = ""
        colonne.Text = ""
    Else
        MsgBox("Vous devez remplir correctement les deux premiers champs!")
    End If
End Sub
End Class

其中"table"(=Table)、"colonne"(=列)和"typede"(=类型)是三个文本框的名称

Visual Studio: 当数据库结构发生变化时重新加载数据集和数据网格

Visual Studio: Reload Dataset and Datagrid when there's structural change in Database

vb.net

datagridview

visual-studio-2013