存储库模式，其中方法占用过多 RAM 并加载不必要的数据

Question

I have an image class.

public int Id{get; set;}
    public string ImageName{get; set;}
    public string CreatedDate{get; set;}
    public string ModifiedDate{get; set;}
    public string Url{get; set;}
 ......... Many more properties 
}

I have 100,000 Images in db. When i use repository Pattern to get images it takes to much memory.

imageRepostery.GetAll().Where(x=> x.Id == 1).ToList();

This line gets all images from database, creates objects, and stores to RAM, then apply where condition and give me 1 image out of 100,000, then again destroy other object 99,999 objects.

How can i use where condition with repository Pattern without getting all data from database.

Edit: And i want to use where condition Like this. List<MyImage> images = imageRepostery.GetAll().Where(x=> x.Id > 500 || x.Id < 1000 ).ToList();

Answer 1

Without implementation of your repository class, it will be all guesses..

Probably your generic implementation of IRepository.GetAll() returns List<T> instead of IEnumerable<T> and basically you are retrieving all your entries every time.

If you like to have single result by Id better refactor your repository and have method like T GetById(int Id) and in its implementation return .SingleOrDefault(x=> x.Id == Id)