![](/img/trans.png)
[英]C# Linq Where Date Between 2 Dates if date stored in database in string format
[英]C# Linq Where Date Between 2 Dates
我正在尝试获取我的 linq 语句以获取两个日期之间的所有记录,但我不太确定需要更改哪些内容才能使其正常工作: (a.Start >= startDate && endDate)
var appointmentNoShow =
from a in appointments
from p in properties
from c in clients
where a.Id == p.OID && (a.Start.Date >= startDate.Date && endDate)
只需将其更改为
var appointmentNoShow = from a in appointments
from p in properties
from c in clients
where a.Id == p.OID &&
(a.Start.Date >= startDate.Date && a.Start.Date <= endDate)
var appointmentNoShow = from a in appointments
from p in properties
from c in clients
where a.Id == p.OID
where a.Start.Date >= startDate.Date
where a.Start.Date <= endDate.Date
var QueryNew = _context.Appointments.Include(x => x.Employee).Include(x => x.city).Where(x => x.CreatedOn >= FromDate).Where(x => x.CreatedOn <= ToDate).Where(x => x.IsActive == true).ToList();
所以你向下滚动,因为答案不起作用:
这就像魔术一样(但他们说它对大数据有效率问题,而且你不像我一样关心)
1-在我的情况下,数据库中的数据类型是“日期时间”和“可空”。
DB中的示例数据格式如下:
2018-11-06 15:33:43.640
转换为字符串时,C# 中的一个类似于:
2019-01-03 4:45:16 PM
所以格式是:
yyyy/MM/dd hh:mm:ss tt
2-所以你需要先以正确的格式准备你的日期时间变量:
示例 1
yourDate.ToString("yyyy/MM/dd hh:mm:ss tt")
示例 2 - 过去 30 天的日期时间范围
DateTime dateStart = DateTime.Now.AddDays(-30);
DateTime dateEnd = DateTime.Now.AddDays(1).AddTicks(-1);
3-最后是你失去一天试图找到的 linq 查询(需要 EF 6)
using System.Data.Entity;
_dbContext.Shipments.Where(s => (DbFunctions.TruncateTime(s.Created_at.Value) >= dateStart && DbFunctions.TruncateTime(s.Created_at.Value) <= dateEnd)).Count();
还要考虑时间比较:
(DbFunctions.CreateDateTime(s.Created_at.Value.Year, s.Created_at.Value.Month, s.Created_at.Value.Day, s.Created_at.Value.Hour, s.Created_at.Value.Minute, s.Created_at.Value.Second) >= dateStart && DbFunctions.CreateDateTime(s.Created_at.Value.Year, s.Created_at.Value.Month, s.Created_at.Value.Day, s.Created_at.Value.Hour, s.Created_at.Value.Minute, s.Created_at.Value.Second) <= dateEnd)
请注意,其他 stackoverflow 问题和答案中提到的以下方法将无法正常工作:
....
&&
(
s.Created_at.Value.Day >= dateStart.Day && s.Created_at.Value.Day <= dateEnd.Day &&
s.Created_at.Value.Month >= dateStart.Month && s.Created_at.Value.Month <= dateEnd.Month &&
s.Created_at.Value.Year >= dateStart.Year && s.Created_at.Value.Year <= dateEnd.Year
)).count();
例如,如果开始日在本月,结束日在下个月,则查询将返回 false 并且没有结果,例如:
DatabaseCreatedAtItemThatWeWant = 2018/12/05
开始日期 = 2018/12/01
结束日期 = 2019/01/04
查询将始终搜索 01 和 04 之间的天数,而不考虑“月”,因此“s.Created_at.Value.Day <= dateEnd.Day”将失败
如果你有非常大的数据,你会执行 Native SQL Query 而不是 linq
...
... where Shipments.Created_at BETWEEN CAST(@Created_at_from as datetime) AND CAST(@Created_at_to as datetime))
....
谢谢
如果有人有兴趣知道如何使用 2 列表和日期之间
var newList = firstList.Where(s => secondList.Any(secL => s.Start > secL.RangeFrom && s.End < secL.RangeTo))
如果您有日期间隔过滤条件,并且您需要选择部分属于此过滤范围的所有记录。 假设:记录具有 ValidFrom 和 ValidTo 属性。
DateTime intervalDateFrom = new DateTime(1990, 01, 01);
DateTime intervalDateTo = new DateTime(2000, 01, 01);
var itemsFiltered = allItems.Where(x=>
(x.ValidFrom >= intervalDateFrom && x.ValidFrom <= intervalDateTo) ||
(x.ValidTo >= intervalDateFrom && x.ValidTo <= intervalDateTo) ||
(intervalDateFrom >= x.ValidFrom && intervalDateFrom <= x.ValidTo) ||
(intervalDateTo >= x.ValidFrom && intervalDateTo <= x.ValidTo)
);
public List<tbltask> gettaskssdata(int? c, int? userid, string a, string StartDate, string EndDate, int? ProjectID, int? statusid) { List<tbltask> tbtask = new List<tbltask>(); DateTime sdate = (StartDate != "") ? Convert.ToDateTime(StartDate).Date : new DateTime(); DateTime edate = (EndDate != "") ? Convert.ToDateTime(EndDate).Date : new DateTime(); tbtask = entity.tbltasks.Include(x => x.tblproject).Include(x => x.tbUser). Where(x => x.tblproject.company_id == c && (ProjectID == 0 || ProjectID == x.tblproject.ProjectId) && (statusid == 0 || statusid == x.tblstatu.StatusId) && (a == "" || (x.TaskName.Contains(a) || x.tbUser.User_name.Contains(a))) && ((StartDate == "" && EndDate == "") || ((x.StartDate >= sdate && x.EndDate <= edate)))).ToList(); return tbtask; }
这是我对基于 searchdata 和开始到结束日期之间的搜索记录的查询
我在让它工作时遇到了问题。
我在 db 行中有两个日期,我需要将它们添加到昨天、今天和明天的列表中。
这是我的解决方案:
var yesterday = DateTime.Today.AddDays(-1);
var today = DateTime.Today;
var tomorrow = DateTime.Today.AddDays(1);
var vm = new Model()
{
Yesterday = _context.Table.Where(x => x.From <= yesterday && x.To >= yesterday).ToList(),
Today = _context.Table.Where(x => x.From <= today & x.To >= today).ToList(),
Tomorrow = _context.Table.Where(x => x.From <= tomorrow & x.To >= tomorrow).ToList()
};
您可以使用DbFunctions.TruncateTime(StartDateTime)
从日期时间中删除时间
var appointmentNoShow =
from a in appointments
from p in properties
from c in clients
where a.Id == p.OID && (DbFunctions.TruncateTime(a.Start) >= DbFunctions.TruncateTime(startDate) && endDate)
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.