OK. My class is in VB.net, it works for jet databases, it connects to 1 db and I'm frankly not sure if it is ready to be shown to the outside world, but it is a class that opens a connection and allows you to execute sql statements.

See if it can help you.

It supports transactions, if that is consideration.

Enjoy ... if that is the right word :)

Imports System.Data.OleDb
Imports System.Configuration
Imports System.Configuration.ConfigurationSettings
Public Class sqlClass
    Public conn As OleDbConnection
    Public t As OleDbTransaction
    Dim openConn As Boolean
    Dim isTransaction As Boolean = False
    Public dt As New DataTable

    Public Function Execute(ByVal sqlString As String) As Integer
        Dim cmd As New OleDbCommand
        Dim da As New OleDbDataAdapter(cmd)
        Me.openConn = False
        If Me.conn Is Nothing Then
            conn = New OleDbConnection(My.Settings.b040_beConnectionString) : conn.Open()
            Me.openConn = True
        End If
        cmd.Connection = conn
        If Left(sqlString, 3) = "qry" Then cmd.CommandType = CommandType.StoredProcedure
        cmd.CommandText = sqlString
        dt.Clear() ' MG 17/apr/11
        da.Fill(Me.dt)
        If Me.openConn Then conn.Close()
        Return dt.Rows.Count
    End Function
    Public Function ExecuteScalar(ByVal sqlString As String) As Object
        Dim cmd As New OleDbCommand
        Dim da As New OleDbDataAdapter(cmd)
        Me.openConn = False
        If (Me.conn Is Nothing) Then
            Me.conn = New OleDbConnection(My.Settings.b040_beConnectionString) : Me.conn.Open()
            Me.openConn = True
        End If
        If (Me.conn.State <> ConnectionState.Open) Then
            Me.conn = New OleDbConnection(My.Settings.b040_beConnectionString) : Me.conn.Open()
            Me.openConn = True
        End If
        cmd.Connection = Me.conn
        If Me.t IsNot Nothing Then cmd.Transaction = Me.t
        cmd.CommandText = sqlString
        Dim o = cmd.ExecuteScalar
        If Me.openConn Then conn.Close()
        Return o
    End Function
    Public Function ExecuteNonQuery(ByVal sqlString As String, ByVal t As OleDbTransaction) As Long
        ' MG 23/feb/11
        Dim cmd As New OleDbCommand
        Dim da As New OleDbDataAdapter(cmd)
        Me.openConn = False
        If Me.conn Is Nothing Then
            Me.conn = New OleDbConnection(My.Settings.b040_beConnectionString) : Me.conn.Open()
            Me.openConn = True
        End If
        If (Me.conn.State <> ConnectionState.Open) Then
            Me.conn = New OleDbConnection(My.Settings.b040_beConnectionString) : Me.conn.Open()
            Me.openConn = True
        End If
        cmd.Transaction = t
        cmd.Connection = Me.conn
        cmd.CommandText = sqlString
        Dim tally As Long
        Try
            tally = cmd.ExecuteNonQuery
        Catch ex As Exception
            Throw New InvalidOperationException(sqlString & vbLf & ex.Message)
        End Try

        If Me.openConn Then Me.conn.Close()
        Return tally
    End Function
    Public Function ExecuteNonQuery(ByVal sqlString As String) As Long
        Dim cmd As New OleDbCommand
        Dim da As New OleDbDataAdapter(cmd)
        Me.openConn = False
        If Me.isTransaction = False Then
            If Me.conn Is Nothing Then
                Me.conn = New OleDbConnection(My.Settings.b040_beConnectionString) : Me.conn.Open()
                Me.openConn = True
            End If
            If (Me.conn.State <> ConnectionState.Open) Then
                Me.conn = New OleDbConnection(My.Settings.b040_beConnectionString) : Me.conn.Open()
                Me.openConn = True
            End If
        End If
        cmd.Connection = Me.conn
        cmd.Transaction = Me.t
        cmd.CommandText = sqlString
        Dim tally As Long
        Try
            tally = cmd.ExecuteNonQuery
        Catch ex As Exception
            Throw New InvalidOperationException(sqlString & vbLf & ex.Message)
        End Try
        If Me.openConn Then Me.conn.Close()
        Return tally
    End Function
    Public Function RetrieveNewKey(Optional ByVal t As OleDbTransaction = Nothing) As Long
        Dim cmd As New OleDbCommand
        Dim da As New OleDbDataAdapter(cmd)
        If Me.isTransaction Then t = Me.t
        Me.openConn = False
        If (Me.conn Is Nothing) Then
            Me.conn = New OleDbConnection(My.Settings.b040_beConnectionString) : Me.conn.Open()
            Me.openConn = True
        End If
        If (Me.conn.State <> ConnectionState.Open) Then
            Me.conn = New OleDbConnection(My.Settings.b040_beConnectionString) : Me.conn.Open()
            Me.openConn = True
        End If
        cmd.Connection = Me.conn
        If t IsNot Nothing Then cmd.Transaction = t
        cmd.CommandText = "select @@identity"
        Dim n As Long = cmd.ExecuteScalar
        If Me.openConn Then conn.Close()
        Return n
    End Function
    Function openTable(ByVal c As String) As DataTable
        Dim cmd As New OleDbCommand
        Dim da As New OleDbDataAdapter(cmd)
        Me.openConn = False
        If (Me.conn Is Nothing) Then
            Me.conn = New OleDbConnection(My.Settings.b040_beConnectionString) : Me.conn.Open()
            Me.openConn = True
        End If
        If (Me.conn.State <> ConnectionState.Open) Then
            Me.conn = New OleDbConnection(My.Settings.b040_beConnectionString) : Me.conn.Open()
            Me.openConn = True
        End If
        cmd.Connection = Me.conn
        cmd.Transaction = t
        cmd.CommandType = CommandType.TableDirect
        cmd.CommandText = c
        Me.dt.Clear()
        da.Fill(Me.dt)
        If Me.openConn Then conn.Close()
        Return Me.dt
    End Function
    Shared Function cDateForJet(ByVal d As Date) As String
        Return "#" & d.ToString("MM/dd/yyyy") & "#"
    End Function
    Shared Function c(ByVal cString As String) As String
        Return Chr(34) & cString & Chr(34)
    End Function
    Shared Function cDoubleForjet(ByVal n As Double) As String
        Dim c As String : c = CStr(n)
        Dim i As Integer
        For i = 1 To Len(c)
            If Mid(c, i, 1) = "," Then Mid(c, i, 1) = "."
        Next
        cDoubleForjet = c
    End Function
    Public Sub beginTransaction()
        conn = New OleDbConnection(My.Settings.b040_beConnectionString) : conn.Open()
        Me.openConn = True
        Me.t = conn.BeginTransaction
        Me.isTransaction = True
    End Sub
    Public Sub commitTransation()
        Me.t.Commit()
        Me.conn.Close()
    End Sub
    Public Shared Function cDataFolder() As String
        Dim conn As New OleDbConnection(My.Settings.b040_beConnectionString)
        Dim c As String = conn.DataSource
        Dim o As New IO.FileInfo(c)
        Return o.DirectoryName
    End Function
    Public Shared Function cLike(ByVal c As String) As String
        Return "'%" & Trim(c) & "%'"
    End Function
    Class SqlBuilder
        Dim odict As New Dictionary(Of String, String)
        Public cTable As String
        Sub addInsert(ByVal cField, ByVal cValue)
            Me.odict.Add(cField, cValue)
        End Sub
        Function cInsert() As String
            Dim cFields As String = "" : Dim cValues As String = ""
            For Each entry As KeyValuePair(Of String, String) In Me.odict
                cFields &= entry.Key & ","
                cValues &= entry.Value & ","
            Next
            cFields = "(" & Left(cFields, Len(cFields) - 1) & ")"
            cValues = "(" & Left(cValues, Len(cValues) - 1) & ")"
            Return "insert into " & Me.cTable & " " & cFields & " values " & cValues
        End Function
    End Class

End Class

>I've been asked to write a class library in C# which will open a connection to an SQL server and do some various updates, deletes, inserts, and so forth in some various tables that exist in two databases on that server. I have never created a class library before and while I've found a couple of examples on the net....they are way too simplistic to really be of much value. Does anyone know of a good sample(s) of class libraries that work with SQL server that I could look at?