/*
            ColumnsClip<T> columnsClip = new ColumnsClip<T>(Expression.Lambda<Func<T, T>>(Expression.Call(null, (MethodInfo)methodof(ExpressionExt.Columns), new Expression[] { expression = Expression.Parameter(typeof(T), "t"), Expression.NewArrayInit(typeof(object), new Expression[] { Expression.Convert(Expression.Call(null, (MethodInfo)methodof(ExpressionExt.As), new Expression[] { Expression.Call(null, (MethodInfo)methodof(ExpressionExt.CountAll), new Expression[] { Expression.Convert(expression, typeof(IEntity)) }), Expression.Constant("TotalCount", typeof(string)) }), typeof(object)) }) }), new ParameterExpression[] { expression }));

            */

            int num = 0;
            var columnsClip = new ColumnsClip<T>((t) => t.Columns(t.CountAll().As("TotalCount")));