SoftDeleteInterceptor

 public class SoftDeleteInterceptor : IDbCommandTreeInterceptor
    {
        public void TreeCreated(DbCommandTreeInterceptionContext interceptionContext)
        {
            if (interceptionContext.OriginalResult.DataSpace!= DataSpace.SSpace)
            {
                return;
            }

            var tree = interceptionContext.Result as DbQueryCommandTree;

            if (tree == null)
            {
                return;
            }

            var newQuery = tree.Query.Accept(new SoftDeleteQueryVisitor());

            interceptionContext.Result = new DbQueryCommandTree(
                tree.MetadataWorkspace,
                tree.DataSpace,
                newQuery);
        }
    }