From your question I assume that you asking how to query a database using c#? String connString = ConfigurationManager.ConnectionStrings[NorthwindConnectionString].ToString(); String sSQL = select * from dbo.Categories ; using (SqlConnection conn = new SqlConnection(connString)) { using (SqlCommand cmd = new SqlCommand()) { conn.Open(); cmd.CommandText = sSQL; cmd.Connection = conn; using (SqlDataReader dr = cmd.ExecuteReader(System.Data.CommandBehavior.CloseConnection)) { using (DataSet result = new DataSet()) { result.Load(dr); } } } }