如何使用VB.net在MS Access数据库中编写主键列

您是一个新手，正在学习如何开发一个程序，该程序可以在保存前检查数据库主键列中是否存在某个值，如果存在，则会显示一条消息，指示该数据已退出.

我正在使用ms access db

这是我的代码:

此代码将数据推送到我的表中Ref列保存txtid.text数据
这是ms access dbase中的主键

私有Sub btnsave_Click(ByVal发送者为System.Object，ByVal e为System.EventArgs)处理btnsave.Click

昏暗的cmd作为新的OleDb.OleDbCommand

如果不是con.State = ConnectionState.Open然后
con.Open()
如果结束

cmd.Connection = con

cmd.CommandText =将条目插入(Ref，Fname，Mname，Comment，Gender)"& _
"VALUES("& Me.txtid.Text&，"& Me.txtfname.Text&"，"& _
Me.txtmname.Text& "，"& Me.txtcom.Text& "，"& _
Mebogen文本和")"
cmd.ExecuteNonQuery()
''刷新表列表中的数据
Refreshdata()


谢谢

Hi am a newbie learning how to develope a program that can check whether a value exist in the database primary key column before saving it, if it exists it shows a message indicating that that data exits.

I am using ms access db

here is my code:

this code pushes the data into my table the Ref column holds the txtid.text data
which is the primary key in ms access dbase

Private Sub btnsave_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnsave.Click

Dim cmd As New OleDb.OleDbCommand

If Not con.State = ConnectionState.Open Then
con.Open()
End If

cmd.Connection = con

cmd.CommandText = "INSERT INTO entries(Ref,Fname,Mname,Comment,Gender)" & _
"VALUES(" & Me.txtid.Text & ",''" & Me.txtfname.Text & "'',''" & _
Me.txtmname.Text & "'',''" & Me.txtcom.Text & "'',''" & _
Me.cbogen.Text & "'')"
cmd.ExecuteNonQuery()
''refresh data in table list
Refreshdata()


Thanks