Linq条件包含

Question

I am trying to find the most efficient way to solve this problem:

I am retrieving a File from the database. If the FileSize is less than 10MB I want to include the FileContent, otherwise that will be left null. My code as of right now is:

var z = QuerySet.AsQueryable();

File f = z.FirstOrDefault(item => item.Id == id && item.FileSize >= 1024 * 1024 * 10);

if (f != null) return f;

return z.Include(a => a.FileContent)
    .FirstOrDefault(item => item.Id == id);

So, I query to find if it is my file (matched Id) and if it is a big file. If so, return the file. Otherwise do the query again, but include the file content. Is there a more efficient way to accomplish this?

Answer 1

How about:

var item = z.Select(x => new {
        File = x,
        Content = x.FileSize >= sizeLimit ? null : x.FileContent
    }).FirstOrDefault(x => x.File.Id == id);

return item.File;

Should make the trick, but you'd have to confirm by looking at generated SQL.