CCN.Modules.Car.DataAccess.CarDataAccess.GetWhere C# (CSharp) Метод

        public string GetWhere(CarGlobalQueryModel query)
        {
            var sqlWhere = new StringBuilder(""); //在售和已售车辆
            //省份
            if (query.provid != null)
            {
                sqlWhere.Append($" and a.provid={query.provid}");
            }

            //城市
            if (query.cityid != null)
            {
                sqlWhere.Append($" and a.cityid={query.cityid}");
            }

            //品牌
            if (query.brand_id != null && query.brand_id != 0)
            {
                sqlWhere.Append($" and a.brand_id={query.brand_id}");
            }

            //车系
            if (query.series_id != null && query.series_id != 0)
            {
                sqlWhere.Append($" and a.series_id={query.series_id}");
            }

            //车型
            if (query.model_id != null && query.model_id != 0)
            {
                sqlWhere.Append($" and a.model_id={query.model_id}");
            }

            //销售价大于..
            if (query.minprice.HasValue)
            {
                sqlWhere.Append($" and a.price>={query.minprice}");
            }

            //销售价小于..
            if (query.maxprice.HasValue)
            {
                sqlWhere.Append($" and a.price<={query.maxprice}");
            }

            //上牌时间 <
            if (query.minyear.HasValue)
            {
                var date = DateTime.Now.AddYears(-query.minyear.Value).ToShortDateString();
                sqlWhere.Append($" and a.register_date<='{date}'");
            }

            //上牌时间 >
            if (query.maxyear.HasValue)
            {
                var date = DateTime.Now.AddYears(-query.maxyear.Value).ToShortDateString();
                sqlWhere.Append($" and a.register_date>='{date}'");
            }

            //行驶里程 >
            if (query.minmileage.HasValue)
            {
                sqlWhere.Append($" and a.mileage>='{query.minmileage}'");
            }

            //行驶里程 <
            if (query.maxmileage.HasValue)
            {
                sqlWhere.Append($" and a.mileage<='{query.maxmileage}'");
            }

            //颜色
            if (query.colorid.HasValue)
            {
                sqlWhere.Append($" and a.colorid={query.colorid}");
            }

            //排量
            if (!string.IsNullOrWhiteSpace(query.liter))
            {
                sqlWhere.Append($" and c3.liter='{query.liter.Trim()}'");
            }

            //变速箱类型
            if (!string.IsNullOrWhiteSpace(query.gear))
            {
                sqlWhere.Append($" and c3.geartype='{query.gear.Trim()}'");
            }

            //车源类型
            if (query.type.HasValue)
            {
                sqlWhere.Append($" and a.seller_type={query.type}");
            }

            //关键字搜索
            if (!string.IsNullOrWhiteSpace(query.keyword))
            {
                sqlWhere.Append($" and (c1.brandname like '%{query.keyword}%' or c2.seriesname like '%{query.keyword}%' or a.carno='{query.keyword}')");
            }
            return sqlWhere.ToString();
        }