求VB.NET2010操作ACCESS数据库的完整代码

Imports System.Data.OleDb
Public Class Parking

Private Sub Parking_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Now_Timer.Enabled = True
End Sub

Private Sub Now_Timer_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Now_Timer.Tick
Now_Time_Label.Text = "当前时间：" & Date.Now
End Sub

Private Sub Enter_Button_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Enter_Button.Click
'定义一个OLEDB连接字符串
Dim conStr As String = "Provider=Microsoft.Jet.OLEDB.4.0; Data Source=F:\test\test.mdb"
'实例化OLEDB连接
Dim con As OleDbConnection = New OleDbConnection(conStr)

Dim sql As New System.Text.StringBuilder
'定义数据库插入语句
sql.Append("insert into Time_billing([Car_Num],[Enter_Time])")
sql.Append("values('" & Trim(Car_Num_Text.Text) & "','" & Date.Now & "')")
'打开数据库链接
con.Open()
'定义执行命令
Dim cmd As New System.Data.OleDb.OleDbCommand(sql.ToString, con)
'执行命令
cmd.ExecuteNonQuery()
'关闭数据库链接
con.Close()
MsgBox("提交成功！")
End Sub

Private Sub Leave_Button_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Leave_Button.Click
Dim Time_Length As Double
Dim Pack_Fee As Double
Dim Enter_time As Date
Dim Leave_time As Date
Dim conStr As String = "Provider=Microsoft.Jet.OLEDB.4.0; Data Source=F:\test\test.mdb"
Dim con As OleDbConnection = New OleDbConnection(conStr)
Dim selSql As New System.Text.StringBuilder
Dim inSql As New System.Text.StringBuilder
Dim upSql As New System.Text.StringBuilder
Dim delSql As New System.Text.StringBuilder
Dim dr As OleDbDataReader

con.Open()
'SQL拼接过程中最后不需要有分号
'在赋值时，读取字段值时必须使用在数据库客户端查询时显示的字段名
selSql.Append("select")
selSql.Append(" Enter_Time")
selSql.Append(" from [Time_billing]")
selSql.Append("where Car_Num = '").Append(Trim(Car_Num_Text.Text)).Append("'")

Dim selcmd As New OleDb.OleDbCommand(selSql.ToString, con)

dr = selcmd.ExecuteReader()
If dr.Read() Then
Enter_time = dr("Enter_Time")
Leave_time = Date.Now
Else
MsgBox("木有数据！")
End If

Enter_Time_Text.Text = Enter_time
Leave_Time_Text.Text = Leave_time
'求时间差
Time_Length = Math.Round(DateDiff(DateInterval.Minute, Enter_time, Leave_time) / 60, 2)

Pack_Fee = Time_Length * 5
Pack_Fee_Text.Text = Pack_Fee

inSql.Append("update [Time_billing]")
inSql.Append(" set [Leave_Time] = '").Append(Trim(Leave_Time_Text.Text)).Append("'")
inSql.Append(" ,[Packing_Fee] = '").Append(Pack_Fee).Append("'")
inSql.Append("where Car_Num = '").Append(Trim(Car_Num_Text.Text)).Append("'")
Dim incom As New OleDb.OleDbCommand(inSql.ToString, con)
incom.ExecuteNonQuery()
'con.Close()
MsgBox("结算完成！")

'con.Open()
upSql.Append("insert into Time_billing_History([Car_Num],[Enter_Time],[Leave_Time],[Packing_Fee])")
upSql.Append(" select")
upSql.Append(" [Car_Num]")
upSql.Append(",[Enter_Time]")
upSql.Append(",[Leave_Time]")
upSql.Append(",[Packing_Fee]")
upSql.Append(" from [Time_billing]")
upSql.Append("where [Car_Num] = '").Append(Trim(Car_Num_Text.Text)).Append("'")
Dim upcom As New OleDb.OleDbCommand(upSql.ToString, con)
upcom.ExecuteNonQuery()

delSql.Append("delete")
delSql.Append(" from")
delSql.Append(" [Time_billing]")
delSql.Append(" where [Car_Num] = '").Append(Trim(Car_Num_Text.Text)).Append("'")
Dim delcom As New OleDb.OleDbCommand(delSql.ToString, con)
delcom.ExecuteNonQuery()
con.Close()
End Sub

Private Sub Clear_Button_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Clear_Button.Click
Car_Num_Text.Clear()
Enter_Time_Text.Clear()
Leave_Time_Text.Clear()
Pack_Fee_Text.Clear()
End Sub
End Class

我有的。。。。。。。。。。。。。。。。。。。。。。