一些更改后数据自动删除[重复]

Question

我创建了一个项目。我想在我运行form2表单的时候菜单栏记录会自动显示出来。

access database
vb.net 2010
connecting through coding 
use connecting module
------------------------------------
in form load event 
call connection
call showdata '---*I want to when I run the form2 form menu bar record will show automatically.
----------------------------------------------
call showdata coding

    cnn = New OleDb.OleDbConnection
    With cnn
        .ConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|\DB.accdb;Persist Security Info=False;"
        .Open()
    End With
    Dim ds As New DataSet
    Dim dt As New DataTable
    ds.Tables.Add(dt)
    Dim da As New OleDb.OleDbDataAdapter
    da = New OleDb.OleDbDataAdapter("select * from cominfo", cnn)
    da.Fill(dt)
    cnn.Close()
    If dt.Rows.Count = 0 Then
        MsgBox("No Company Name Registerd. Please Registered The Company....", vbOKOnly)
        Cominfo.Show()
        Cominfo.ComnameTextBox.Focus()
    Else
        Cominfo.IDTextBox.Text = dt.Rows(0).Item(0)
        Cominfo.ComnameTextBox.Text = dt.Rows(0).Item(1)
    End If

添加数据后完美显示数据的编码

但是当我进行其他任何更改编码时（例如，我添加了一个用于显示日期时间的文本框）并保存然后运行应用程序并转到 form2，所有记录都会自动删除。然后我添加记录并停止应用程序然后运行100次正常工作但是当我在删除/添加编码窗口的一些空白区域后按下保存按钮时，当我运行应用程序并打开form2时没有记录。

我使用此代码在数据上插入数据

基础模块

Imports System.Data.OleDb
Module Modconnection
Public cnn, cn As New OleDb.OleDbConnection
Public cm As New OleDb.OleDbCommand
Public dr As OleDbDataReader

Public Sub connection()
    cn = New OleDb.OleDbConnection
    With cn
        .ConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|\DB.accdb;Persist Security Info=False;"
        .Open()
    End With
End Sub

添加数据按钮：

    Call connection()
    Try

        cm = New OleDb.OleDbCommand
        With cm
            .Connection = cn
            .CommandType = CommandType.Text
            .CommandText = "INSERT INTO cominfo (Comname,Add1,Add2,Phone,Vat,cst_tin,Email,Website) VALUES (@Comname,@Add1,@Add2,@Phone,@Vat,@cst_tin,@Email,@Website)"

            .Parameters.Add(New System.Data.OleDb.OleDbParameter("@Comname", System.Data.OleDb.OleDbType.VarChar, 255, Me.ComnameTextBox.Text))
            .Parameters.Add(New System.Data.OleDb.OleDbParameter("@Add1", System.Data.OleDb.OleDbType.VarChar, 255, Me.Add1TextBox.Text))
            .Parameters.Add(New System.Data.OleDb.OleDbParameter("@Add2", System.Data.OleDb.OleDbType.VarChar, 255, Me.Add2TextBox.Text))
            .Parameters.Add(New System.Data.OleDb.OleDbParameter("@Phone", System.Data.OleDb.OleDbType.VarChar, 255, Me.PhoneTextBox.Text))

            .Parameters.Add(New System.Data.OleDb.OleDbParameter("@Vat", System.Data.OleDb.OleDbType.VarChar, 255, Me.VatTextBox.Text))
            .Parameters.Add(New System.Data.OleDb.OleDbParameter("@cst_tin", System.Data.OleDb.OleDbType.VarChar, 255, Me.Cst_tinTextBox.Text))
            .Parameters.Add(New System.Data.OleDb.OleDbParameter("@Email", System.Data.OleDb.OleDbType.VarChar, 255, Me.EmailTextBox.Text))
            .Parameters.Add(New System.Data.OleDb.OleDbParameter("@Website", System.Data.OleDb.OleDbType.VarChar, 255, Me.WebsiteTextBox.Text))


            ' RUN THE COMMAND
            cm.Parameters("@Comname").Value = Me.ComnameTextBox.Text
            cm.Parameters("@Add1").Value = Me.Add1TextBox.Text
            cm.Parameters("@Add2").Value = Me.Add2TextBox.Text
            cm.Parameters("@Phone").Value = Me.PhoneTextBox.Text

            cm.Parameters("@Vat").Value = Me.VatTextBox.Text
            cm.Parameters("@cst_tin").Value = Me.Cst_tinTextBox.Text
            cm.Parameters("@Email").Value = Me.EmailTextBox.Text
            cm.Parameters("@Website").Value = Me.WebsiteTextBox.Text

            cm.ExecuteNonQuery()
            MsgBox("Record saved.", MsgBoxStyle.Information)


            Me.ComnameTextBox.Text = ""
            Me.Add1TextBox.Text = ""
            Me.Add2TextBox.Text = ""
            Me.PhoneTextBox.Text = ""

            Me.VatTextBox.Text = ""
            Me.Cst_tinTextBox.Text = ""
            Me.EmailTextBox.Text = ""
            Me.WebsiteTextBox.Text = ""



            Exit Sub
        End With
    Catch ex As Exception
        MsgBox(ex.Message, MsgBoxStyle.Critical)
    End Try

Answer 1

我只是将 db.accdb 属性副本更改为输出目录“请勿复制”

Answer 2

您缺少的是您只是在本地 DataTable 中编辑数据，所以如果您退出并返回程序，它就消失了！

所以你需要做的是创建一个 OleDb 命令并创建一个“插入”语句或一个“更新”语句。我会给你一个包含更多信息的链接。

https://msdn.microsoft.com/en-us/library/system.data.oledb.oledbdataadapter.insertcommand(v=vs.110).aspx

https://msdn.microsoft.com/en-us/library/5yeecx59(v=vs.110).aspx

编辑：一个展示工作代码的好视频（不是我的）： https://www.youtube.com/watch?v=MWP8geR76kI