Imports System.Data
Imports System.Data.SqlClient

Public Class DB
    Dim con As SqlConnection
    Dim cmd As SqlCommand

    Dim i As Integer

    Public Sub New()
        con = New SqlConnection("server=DESKTOP-M9MDGJN\SQLEXPRESS; database=testdb; integrated security=true")

    End Sub

    Public Function doInsert(vSQL As String)
        doOpen()

        cmd = New SqlCommand(vSQL, con)
        i = cmd.ExecuteNonQuery()

        doClose()

        Return 0
    End Function

    Public Function doUpdate(vSQL As String)
        doOpen()

        cmd = New SqlCommand(vSQL, con)
        i = cmd.ExecuteNonQuery()

        doClose()

        Return 0
    End Function


    Public Function doDelete(vSQL As String)
        doOpen()

        cmd = New SqlCommand(vSQL, con)
        i = cmd.ExecuteNonQuery()

        doClose()

        Return 0
    End Function
    Public Function doRetrieve(vSQL As String) As SqlDataReader

        Dim rs As SqlDataReader

        doOpen()

        cmd = New SqlCommand(vSQL, con)
        rs = cmd.ExecuteReader()

        Return rs
    End Function

    Private Function doOpen()
        con.Open()
    End Function
    Private Function doClose()
        con.Close()
        Return 0
    End Function
End Class