Class to for common DB Functions

Hi to all,

I am coding a database access class to use for common database function like returning a sqldatareader based on the sql query provided.

Find below the code for it:

Imports System.Data
Imports System.Data.SqlClient
Imports System.Data.OleDb

Public Class DBLib

    Private _constr As String

    Public sqlDBUser_ As String
    Public sqlDBPass_ As String
    Public sqlDBName_ As String
    Public sqlDBServer_ As String

    Public Property ConnectionString() As String
        Get
                _constr = "Data Source=" & sqlDBServer_ & ";Initial Catalog=" & sqlDBName_ & ";User ID=" & sqlDBUser_ & ";Password=" & sqlDBPass_ & ";Integrated Security=false;"          
            Return _constr
        End Get

        Set(ByVal value As String)
            _constr = value
        End Set

    End Property

    Public Function TestSQLConnection() As Boolean
        Dim retVal As String = False

        Try
            Dim con As New SqlConnection
            con.ConnectionString = Me.ConnectionString
            con.Open()
            retVal = True
            con.Close()
        Catch ex As Exception
            retVal = False
        End Try

        Return retVal

    End Function


    Public Function SelectRowsSQL(ByVal sSql As String) As SqlDataReader
        Try
            Dim con As New SqlConnection
            con.ConnectionString = Me.ConnectionString
            con.Open()

            Dim dr As SqlDataReader
            Dim cmd As New SqlCommand(sSql, con)
            dr = cmd.ExecuteReader
            con.Close()

            Return dr
        Catch ex As Exception
            MsgBox(ex.Message)
            Return Nothing
        End Try

    End Function
End Class

Need you valuable suggestion regarding the best coding practices for the database access like performance and exception handlings.

Thx

M@F
Index was outside the bounds !!!