Question

我有一个关于如何将以下内容转换为linq的问题。我一直试图了解ASP.NET MVC，对我来说最大的障碍之一就是Linq。

CREATE PROCEDURE [dbo].[SelectAvailableCoops]
    @startDate DATETIME, @endDate DATETIME
AS
BEGIN
    SET NOCOUNT ON;

    SELECT ID, coopName, coopCPN
    FROM tbl_Coops
    WHERE ID NOT IN (SELECT coopID
                     FROM tbl_bookings 
                     WHERE (startDate <= @startDate AND endDate >= @startDate)
                        OR (startDate < @endDate AND endDate >= @endDate)
                        OR (@startDate <= startDate AND @endDate >= endDate)
                    )
END
GO

如果有帮助，目前我的行动结果中有以下内容。

BookingsListVM bookinglist = new BookingsListVM();
//bookinglist.Customers = db.Customers.ToList();
bookinglist.Customers = (from c in db.Customers select c).ToList();
bookinglist.CustomerBookings = (from cb in db.CustomerBookings select cb).ToList();
bookinglist.Coops = (from co in db.Coops select co).ToList();

Answer 1

这里有一个

db.Customers.Where(x=> db.CustomerBookings.Any(a=> a.coopID != x.Id && 
((a.StartDate <= startDate && a.EndDate >= enddate)
|| 
(a.StartDate < endDate && a.EndDate >= enddate)
||
(a.StartDate <= startDate && a.EndDate >= endDate)
)));

Answer 2

另一个答案看起来更好，但这是一个稍长的解决方案，希望更容易理解。

  //Returns IDs
       var bookingIds = tbl_bookings
             .Where(b => b.ReleaseDate <= startDate && b.ReleaseDate >= endDate
                 || (b.ReleaseDate < endDate && b.ReleaseDate >= endDate)
                 || (b.ReleaseDate <= startDate && b.ReleaseDate >= endDate))
             .Select(b => b.Id);

  //Returns anonymous object list containing all records
  //with an ID not found in previous result set
       var bookings = tbl_bookings.Where(b => !bookingIds.Contains(b.Id))
             .Select(b => new { ID = b.Id, CoopName = b.Id, coopCPN = b.Id })
             .ToList();

将我的存储过程更改为Linq

2 个答案: