Entity framework 实体框架。使用匿名类型和投影选择Many
我有一个多包的横幅。每个包有多个文件 我有以下疑问:Entity framework 实体框架。使用匿名类型和投影选择Many,entity-framework,Entity Framework,我有一个多包的横幅。每个包有多个文件 我有以下疑问: List<BannerModel> models = context.Banners .Select(x => x.Packs .SelectMany(p => p.Files, (p, f) => new { Id = p.Id, Flag = p.Flag, File = new { Id = f.Id, Flag = f.Flag, K
List<BannerModel> models = context.Banners
.Select(x => x.Packs
.SelectMany(p => p.Files, (p, f) => new {
Id = p.Id,
Flag = p.Flag,
File = new { Id = f.Id, Flag = f.Flag, Key = f.Key, Mime = f.Mime }
})
.Where(a => a.File.Flag == "Img_200")
.Select(a => new BannerModel { PackId = a.Id, ImageKey = a.File.Key })
).ToList();
奇怪的是,我得到了10个项目,5个有数据,5个没有数据
我应该只得到5个项目的列表。满足标准的那个
有人能帮我解决这个问题吗
谢谢,,
米格尔应该是:
List<BannerModel> models = context.Banners
.SelectMany(x => x.Packs
.SelectMany(p => p.Files, (p, f) => new {
Id = p.Id,
Flag = p.Flag,
File = new { Id = f.Id, Flag = f.Flag, Key = f.Key, Mime = f.Mime }
})
.Where(a => a.File.Flag == "Img_200")
.Select(a => new BannerModel { PackId = a.Id, ImageKey = a.File.Key })
).ToList();
List models=context.banner
.SelectMany(x=>x.Packs)
.SelectMany(p=>p.Files,(p,f)=>new{
Id=p.Id,
Flag=p.Flag,
File=new{Id=f.Id,Flag=f.Flag,Key=f.Key,Mime=f.Mime}
})
.Where(a=>a.File.Flag==“Img_200”)
.Select(a=>newbannermodel{PackId=a.Id,ImageKey=a.File.Key})
).ToList();
List<BannerModel> models = context.Banners
.SelectMany(x => x.Packs
.SelectMany(p => p.Files, (p, f) => new {
Id = p.Id,
Flag = p.Flag,
File = new { Id = f.Id, Flag = f.Flag, Key = f.Key, Mime = f.Mime }
})
.Where(a => a.File.Flag == "Img_200")
.Select(a => new BannerModel { PackId = a.Id, ImageKey = a.File.Key })
).ToList();