public void BuildFilters()
        {
            var builder = new ExpressionBuilder <User>();
            var filters = new List <SqlFilter>();

            filters.Add(SqlFilter.Create("Id", Operation.Equal, 1));
            filters.Add(SqlFilter.Create("LastLoginDate", Operation.GreaterThan, DateTime.Now));
            filters.Add(SqlFilter.Create("Username", Operation.Like, "aaaa"));
            filters.Add(SqlFilter.Create("Id", Operation.List, new int[] { 1, 2, 3 }));
            filters.Add(SqlFilter.Create("Password", Operation.NotEqual, "1"));
            filters.Add(SqlFilter.Create("Status", Operation.List, new int[] { 1 }));
            var where = builder.Build(filters, new Dictionary <string, string>());
            var results = db.Set <User>().Where(where).ToList();

            Console.WriteLine(results.Count + "条数据");
        }