Question

我有一个对象＆＃34; Property＆＃34;有孩子的＆＃34; Notes＆＃34;和＆＃34;附件＆＃34;。我想带回整个＆＃34; Property＆＃34;，所有相关的＆＃34; Notes＆＃34;但只有一个字段来自＆＃34;附件＆＃34;。我不想带回整个＆＃34;附件＆＃34;因为它包含巨大的base64图像。如果我需要这些，我可以通过＆＃34; AttachmentId＆＃34;来获取它们。问题是在使用Lambda Include时如何缩小字段范围。以下不起作用。我真的不想创建一个冗长的LINQ语句

var property = await _context.Property
                .Include(x => x.Notes)
                .Include(x => x.Attachments.Select(y => new PropertyAttachment
                {
                    PropertyId = y.PropertyId,
                    AttachmentId = y.AttachmentId,
                    Type = y.Type,
                    Title = y.Title,
                    Content = ""
                }).ToList())
                .SingleOrDefaultAsync(x => x.PropertyId == key);

Answer 1

使用选择和匿名类型，您可以这样尝试

var property = _context.Property.Select(x => new 
   { Property = x,
     HMOUnits = x.HMOUnits,
     Notes = x.Notes,
     AttachmendId = new { Id = x.Attachments.Select(z=> z.AttachmentId) }
   })
   .SingleOrDefaultAsync(x =>
        x.Property.ID == key &&
       (RestrictUser(User) ? x.Property.Tenancies.Any(y => y.Assignments.Any(z => z.Tenant.UserID == Convert.ToInt32(User.Identity.Name))) : true) 
   );

Lambda包含限制列

1 个答案: