Free Programming Tutorials & Source Code

This function can be used to get the latest integer key value in a database, and add one to it to insert a new record without duplicated keys. You can put it in a module and call it from anywhere in your application.
If a table has no records in it, it returns 0, then add one to it.

  
Public Function GetID(ByVal TblName As String) As Integer 
Dim cn As New db          
Dim x As Integer         
Dim cmd As New OleDb.OleDbCommand
cmd.Connection = cn.GetConnection         ' you can use your own code to connect to the DB
cmd.CommandType = CommandType.Text         
cmd.CommandText = "Select max(ID) from " & TblName         
cmd.Connection.Open()         
x = CInt(IIf(cmd.ExecuteScalar() Is System.DBNull.Value, 0, cmd.ExecuteScalar()))         
cmd.Connection.Close()         
Return x
End Function  

Hope you find it useful.