Question

我有一个模型，该模型保存列表月份1月-12月。我希望将用户设置为日志示例的开始日期12月26日至1月25日或1月1日-1月31日

 public class SalaryMonth
    {
        public int Id { get; set; }

        public int StartMonth { get; set; }
        public int StartDay { get; set; }

        public int EndMonth { get; set; }
        public int EndDay { get; set; }

        public string Name { get; set; }

    }

如何根据提供的日期获取SalaryMonth，但是这是我的业务逻辑一个月，总是返回null

namespace Contracts.Attendances
{


    public interface IAttendanceService
    {       
        Task<SalaryMonth> GetASalaryMonthByDate(DateTime date);

    }

     public class AttendanceService : IAttendanceService
    {

        /.../

        public async Task<SalaryMonth> GetASalaryMonthByDate(DateTime date) {
        var day = date.Day;
            var month = date.Month;
            var result = await _context.SalaryMonths.
                .FirstOrDefaultAsync(p => (p.StartMonth == month && p.StartDay >= day && p.StartDay <= day) 
                                          || ( p.EndMonth == month && p.EndDay >= day && p.EndDay <= day));

            return result;
        }

    }
}

Json来自数据库

{
    "SalaryMonth": [
        {
            "Id": "3",
            "StartMonth": "2",
            "StartDay": "26",
            "EndMonth": "3",
            "EndDay": "25",
            "Name": "March"
        },
        {
            "Id": "4",
            "StartMonth": "3",
            "StartDay": "26",
            "EndMonth": "4",
            "EndDay": "25",
            "Name": "April"
        },
        {
            "Id": "5",
            "StartMonth": "4",
            "StartDay": "26",
            "EndMonth": "5",
            "EndDay": "25",
            "Name": "May"
        },
        {
            "Id": "6",
            "StartMonth": "5",
            "StartDay": "26",
            "EndMonth": "6",
            "EndDay": "25",
            "Name": "June"
        },
        {
            "Id": "7",
            "StartMonth": "6",
            "StartDay": "26",
            "EndMonth": "7",
            "EndDay": "25",
            "Name": "July"
        },
        {
            "Id": "8",
            "StartMonth": "7",
            "StartDay": "26",
            "EndMonth": "8",
            "EndDay": "25",
            "Name": "August"
        },
        {
            "Id": "9",
            "StartMonth": "8",
            "StartDay": "26",
            "EndMonth": "9",
            "EndDay": "25",
            "Name": "September"
        },
        {
            "Id": "10",
            "StartMonth": "9",
            "StartDay": "26",
            "EndMonth": "10",
            "EndDay": "25",
            "Name": "October"
        },
        {
            "Id": "11",
            "StartMonth": "10",
            "StartDay": "26",
            "EndMonth": "11",
            "EndDay": "25",
            "Name": "November"
        },
        {
            "Id": "12",
            "StartMonth": "11",
            "StartDay": "26",
            "EndMonth": "12",
            "EndDay": "25",
            "Name": "December"
        },
        {
            "Id": "2",
            "StartMonth": "2",
            "StartDay": "26",
            "EndMonth": "2",
            "EndDay": "25",
            "Name": "February"
        },
        {
            "Id": "1",
            "StartMonth": "12",
            "StartDay": "26",
            "EndMonth": "1",
            "EndDay": "25",
            "Name": "January"
        }
    ]
}

如何查询记录以允许用户从提供的日期获得薪水月份。示例用户提供了26/12/2019到26/01/2020之间的任何日期，结果必须为1月，因为该日期为 Jan Month ，因为Jan StartMonth是12，StartDate 26，EndMonth是1，EndDate 25

Answer 1

所以我想我知道您要做什么。如果我理解正确，那么您的linq电话中的逻辑就有些混乱了。给定任意一天，该天不能小于或等于某个日期，也不能大于或等于该同一日期，除非它是同一日期。

所以您需要这样做：

C＃代码：

.FirstOrDefaultAsync(p => (p.StartMonth == month && p.StartDay <= day) || ( p.EndMonth == month && p.EndDay >= day ));

希望这会有所帮助。

日期之间的Linq复杂查询搜索

1 个答案: