c#Dapper mysql按时间段查询和过滤

 #endregion
        /// <summary>
        /// 根据条件获取集合
        /// </summary>
        /// <param name="id">key</param>
        /// <returns>实体</returns>
        public IEnumerable<models.Model.ScanNubProduct> QueryDateSingle(string datestr)
        {
            if (datestr=="oneday")
            {
               
                    string date =  DateTime.Now.AddDays(-1).ToString("yyyyMMdd");          //昨天时间
                    const string sql = "SELECT *  FROM report_daily_newzsnumtotal_copy WHERE   日期 =@日期" + " and 规格 not like '36%'" + " and 规格 not like '21%'";
                    using (MySqlConnection connection = new MySqlConnection(connstr))
                    {
                        connection.Open();
                        return connection.Query<models.Model.ScanNubProduct>(sql, new { 日期 = date });
                    }
            }
            else if(datestr=="week")
            {
                string lastday =  DateTime.Now.AddDays(-1).ToString("yyyyMMdd");
                string weeksday = DateTime.Now.AddDays(-8).ToString("yyyyMMdd");
                //    const string sql = "SELECT *  FROM report_daily_newzsnumtotal_copy WHERE  日期 between  '20180827'  and '20180830'";
                //  string where = "WHERE  日期 between  "+ weeksday + " and "+ lastday+ " and 规格 not like 32 and 规格 not like 36 and 规格 not like 21";
                string where = "WHERE  日期 between  " + weeksday + " and " + lastday + " and 规格 not like '36%'" + " and 规格 not like '21%'";    //过滤规格为36 和21开头的数据
                return QueryList(where); 
            }
            else
            {
                return null;
            }
            }