Navigational Workflows Unleashed in WWF/ASP.NET 3.5

using System;
using System.Linq;

namespace DateSite
{
    /// <summary>
    /// Data layer for CRUD operations.
    /// </summary>
    public class Database
    {
        /// <summary>
        /// Returns the set of all corresponding pairs of Dating IDs and 
        /// navigational Workflow IDs from database.
        /// </summary>
        /// <returns></returns>
        public static object GetExistingProfiles()
        { 
            ProfileDataContext context = new ProfileDataContext();
            var workflows = from p in context.Profiles select new { p.DatingId, p.WorkflowId };
            var resultSet = workflows.ToList();
            context.Dispose();
            return resultSet;
        }

        /// <summary>
        /// Inserts the given profile into the database.
        /// </summary>
        /// <param name="profile"></param>
        public static void InsertProfile(Profile profile)
        {
            // insert the given profile into the database
            ProfileDataContext context = new ProfileDataContext();
            context.Profiles.InsertOnSubmit(profile);
            context.SubmitChanges();
            context.Dispose();
        }

        /// <summary>
        /// Takes the information in the given profile and updates the
        /// corresponding record in the database.
        /// </summary>
        /// <param name="profile"></param>
        public static void UpdateProfile(Profile profile)
        {
            // update the given profile
            ProfileDataContext context = new ProfileDataContext();
            context.Profiles.Attach(profile, true);
            context.SubmitChanges();
            context.Dispose();
        }

        /// <summary>
        /// Returns the profile object with the given dating id from the database.
        /// </summary>
        /// <param name="datingId"></param>
        /// <returns></returns>
        public static Profile SelectProfile(string datingId)
        {
            ProfileDataContext context = new ProfileDataContext();
            Profile profile = (from p in context.Profiles where p.DatingId.Equals(datingId) select p).First();
            context.Dispose();
            return profile;
        }

        /// <summary>
        /// Deletes the given dating id and workflow id records from the database.
        /// </summary>
        /// <param name="datingId"></param>
        /// <param name="workflowId"></param>
        public static void DeleteProfile(string datingId, Guid workflowId)
        {
            ProfileDataContext context = new ProfileDataContext();

            // delete the profile record
            var profile = from p in context.Profiles where p.DatingId.Equals(datingId) select p;
            context.Profiles.DeleteAllOnSubmit(profile);

            // delete the workflow record
            var workflow = from i in context.InstanceStates where i.uidInstanceID.Equals(workflowId) select i;
            context.InstanceStates.DeleteAllOnSubmit(workflow);

            // submit the changes and dispose of the context object
            context.SubmitChanges();
            context.Dispose();
        }
    }
}