使用 EF Core 删除不在范围内的所有实体？

Question

假设我在people表中有一个包含这些条目的数据库：

id | companyId | name 
1  | 9         | Kevin
2  | 9         | Mike
3  | 9         | John

然后我收到这个put请求来更新实体：

[
    {"id": 1, "name": "Kevin"},
    {"id": 2, "name": "Michael"},
    {"id": 0, "name": "Joe"}
]

所以，我需要更新 id 2，删除 id 3，然后添加新实体。 我知道_context.People.UpdateRange(entities)将更新现有实体并添加新实体，但我还需要删除 id 3。基本上，json 请求的内容应该是where companyId = 9的整个 people 表. 我知道我可以这样做：

var currentPeople = _context.People
   .AsNoTracking()
   .Where(e => e.companyId == request.companyId)
   .ToListAsync();

var requestEntities = request
   .Select(m => new PersonEntity(r))
   .ToList();

var peopleToRemove = requestEntities
   .Where(oldEntity => requestEntities.All(e => e.Id != oldEntity.Id))
   .ToList();

using (var transaction = _context.Database.BeginTransaction())
{
    _context.People.RemoveRange(peopleToRemove);
    _context.People.UpdateRange(requestEntities);
    await _context.SaveChangesAsync();
    transaction.Commit();
}

但这太笨重了。 EF Core 是否提供了更好的解决方案？ 谢谢！

Answer 1

您可以执行以下操作：

var existingPeopleList = _context.People.AsNoTracking()
                                 .Where(e => e.companyId == request.companyId) 
                                 .ToListAsync();

var requestEntities = request.Select(r => new PersonEntity(r)).ToList();

var requestedPeopleList = requestEntities.Select(re => new People()
                          {
                              Id = re.Id,
                              CompanyId = 9,
                              Name = re.Name
                          }).ToList();



var peopleToBeRemoved = existingPeopleList.Where(ep => requestedPeopleList.All(rp => rp.Id != ep.Id)).ToList();

var peopleToBeAdded = requestedPeopleList.Where(rp => existingPeopleList.All(ep => ep.Id != rp.Id)).ToList();

var peopleToBeUpdated = requestedPeopleList.Where(rp => existingPeopleList.Any(ep => ep.Id == rp.Id)).ToList();

_context.People.RemoveRange(peopleToBeRemoved);
_context.People.AddRange(peopleToBeAdded);
_context.People.UpdateRange(peopleToBeUpdated);
await _context.SaveChangesAsync();