请问vb.net不用绑定的方法，如何连接数据库？

Public Function OpenConnForAccess(ByVal FileName As String) As ADODB.Connection
Dim AdoConn As New ADODB.Connection
With AdoConn
.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & FileName & ";Persist Security Info=False"
.Open
End With
Set OpenConnForAccess = AdoConn
End Function

Public Function OpenConnForSqlServer(ByVal ServerName As String, ByVal UserId As String, ByVal PassWord As String, Optional ByVal DateBaseName As String = "") As ADODB.Connection
Dim AdoConn As New ADODB.Connection
Dim strConn As String
With AdoConn
strConn = "Provider=SQLOLEDB.1;Persist Security Info=True;User ID=" & UserId & ";Password=" & PassWord & ";Data Source=" & ServerName
If DateBaseName <> "" Then strConn = strConn & ";database=" & DateBaseName
.Connec