Vb.net Visual Studio 使用更新命令时出现问题

您好，我正在从 sql 数据库创建一个搜索功能和更新按钮，我需要能够在其中搜索某些名称等，但还需要能够在数据集中进行更改并保存它们。到目前为止，搜索功能按照我想要的方式工作，但是，更新按钮并没有真正保存更改，因为当我停止并重新启动代码时，即使在我尝试更新它以更改某些值之后，它也会恢复为默认数据集。关于我做错了什么有什么想法吗？您可能建议编辑数据集中的插入和删除值的其他方法？任何事情都有帮助！谢谢你！

Imports System.Data.SqlClient

Imports System.Data.Common

Public Class Form1

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        
        Dim connection As New SqlConnection("Connection String PlaceHolder")
        Dim Table As New DataTable()
        
        Dim Adapter As New SqlDataAdapter("SELECT * FROM TrueTrack1", connection)
        
        Adapter.Fill(Table)
        
        DataGridView1.DataSource = Table
        load_data()



    End Sub



    Private ReadOnly queryTimer As New System.Threading.Timer(AddressOf runQuery, Nothing, -1, -1)
    Private searchName As String
    Private searchType As String
    Private searchIP As String
    Private textChangeQueryDelay As Integer = 1000

    Private Sub TextBoxes_TextChanged(sender As Object, e As EventArgs) Handles TextBox1.TextChanged, TextBox2.TextChanged, TextBox3.TextChanged
        searchName = TextBox1.Text
        searchType = TextBox2.Text
        searchIP = TextBox3.Text
        queryTimer.Change(textChangeQueryDelay, -1)
    End Sub

    Private Sub runQuery(state As Object)
        Dim table = New DataTable()
        Using connection = New SqlConnection("Connection String Placeholder")
            Using command = New SqlCommand()
                command.Connection = connection
                Dim commandText = "SELECT * FROM TrueTrack1 WHERE 1=1 "
                If Not String.IsNullOrEmpty(searchName) Then
                    commandText &= " AND UserName like @name "
                    command.Parameters.Add("@name", SqlDbType.VarChar, 100).Value = "%" & searchName & "%"
                End If
                If Not String.IsNullOrEmpty(searchType) Then
                    commandText &= " AND DeviceType like @type "
                    command.Parameters.Add("@type", SqlDbType.VarChar, 100).Value = "%" & searchType & "%"
                End If
                If Not String.IsNullOrEmpty(searchIP) Then
                    commandText &= " AND IPAddress like @ip "
                    command.Parameters.Add("@ip", SqlDbType.VarChar, 100).Value = "%" & searchIP & "%"
                End If
                command.CommandText = commandText
                Using adapter = New SqlDataAdapter(command)
                    adapter.Fill(table)
                End Using
            End Using
        End Using
        DataGridView1.Invoke(Sub() DataGridView1.DataSource = table)
    End Sub





    Private Sub Button1_Click(sender As Object, e As EventArgs) 

    End Sub

    Dim da As New SqlDataAdapter
    Dim dt As New DataSet

    Private Sub Button1_Click_1(sender As Object, e As EventArgs) Handles Button1.Click
        Dim cmd As New SqlCommandBuilder(da)
        Dim changes As New DataSet
        Dim table As New DataTable()




        changes = dt.GetChanges
        If changes IsNot Nothing Then
            da.Update(changes)
            da.Fill(dt)
            DataGridView1.DataSource = dt.Tables(0)
            load_data()
        End If
    End Sub

    Private Sub load_data()
        Dim conn As New SqlConnection("Connection String Placeholder")
        conn.Open()
        da = New SqlDataAdapter("Select * From TrueTrack", conn)
        dt.Clear()
        da.Fill(dt)
        DataGridView1.DataSource = dt.Tables(0)

        conn.Close()
    End Sub


End Class

为了从DataGridView中更新（包括编辑、插入和删除）数据库和DataTable，您可以参考以下代码。

Private dt As DataTable = New DataTable
Private da As SqlDataAdapter
Private connection As SqlConnection = New SqlConnection("your connection string")
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    DataGridView1.EndEdit()
    da.Update(dt)
End Sub
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    bind_data()
End Sub
Private Sub Form1_FormClosing(sender As Object, e As FormClosingEventArgs) Handles MyBase.FormClosing
    connection.Close()
End Sub
Private Sub bind_data()
    connection.Open()
    Dim cmdTxt As String = "SELECT * FROM TrueTrack"
    da = New SqlDataAdapter(New SqlCommand(cmdTxt, connection))
    Dim builder As SqlCommandBuilder = New SqlCommandBuilder(da)
    da.Fill(dt)
    Dim source As BindingSource = New BindingSource With {
                                    .DataSource = dt
                                  }
    DataGridView1.DataSource = source
End Sub