仅更新给定值 (Entity Framework)

Question

我正在尝试仅通过动态发送到 API 的值来更新实体，因此每次客户端发送到我的 api 不同的值时，它只会更改给定的值。

这是我的实体

    public class Administrator
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public string Email { get; set; }
        public string Password { get; set; }
        public string Role { get; set; }
        public int Phone { get; set; }
    }

这是我的存储库：

public Task<bool> UpdateAdmin(Administrator admin)
        {
            if (admin != null)
            {
                _context.Admins.Update(admin);
                Commit();
                return Task.FromResult(true);
            }
            else
            {
                return Task.FromResult(false);
            }
        }

假设我只想更新 phone 号码，我发送的数据只有新的 phone 号码，但其余属性也更改为 null。我怎样才能只更新给定的？

谢谢

Answer 1

您将需要使用 JsonPatchDocument

这是我做类似事情的示例代码

//get the instance of admin you want to update
var adminInstance = GetAdmin....//get your admin

//partial update -> this how you create a patch doc with C#
var patchDoc = new JsonPatchDocument<Admin>();
patchDoc.Replace(x => x.phone, "put new phone number");//for any other property do x.propertyName
patchDoc.ApplyTo(adminInstance)// apply the patch doc to the instance you want to update
await UpdateAdmin(adminInstance)//your update method look good

//for people trying to do this with an api serialize the patch doc then send it to api
var adminDto =JsonConvert.SerializeObject(patchDoc);



//this is an api example
[HttpPatch("{adminId}")]
public async Task<ActionResult> UpdateAdmin(string adminId, JsonPatchDocument<Admin> patchDocument)
{
  var admin= await _adminRespository.GetAsync(admin);//get the admin you want to update

  patchDocument.ApplyTo(admin); //apply patch doc to the admin

  await _adminRespository.UpdateAsync(admin); //pass admin to your repo

  await _adminRespository.SaveAsync();

  return NoContent();
  }

在 repos 中，您无需做任何复杂的事情，只需将模型作为更新传递即可，所有工作都由 json 补丁文档完成。

要了解有关补丁文档的更多信息

如果你也能用本文提供的解决方案达到同样的效果 Entity Framework validation with partial updates

Answer 2

更新

According to your comment, admin receives different field contents each time.

所以可以用reflection来dynamically判断admin接受的各个字段的值是否为null.如果不是，则替换data.

对应字段的值

public Task<bool> UpdateAdmin(Administrator admin)
        {
            if (admin != null)
            {   
                var data = _context.Admins.Find(admin.Id);
               
                Type t = typeof(Administrator);
                PropertyInfo[] propInfos = t.GetProperties(BindingFlags.Public | BindingFlags.Instance);
                foreach (var item in propInfos)
                {
                   var fieldValue = item.GetValue(admin);
                   if (fieldValue != null)
                   {
                      item.SetValue(data, fieldValue);
                   }
                 }

                  _context.Admins.Update(data);
                  Commit();
                  return Task.FromResult(true);
            }
            else
            {
                return Task.FromResult(false);
            }
        }

仅更新给定值 (Entity Framework)

Update only the given values (Entity Framework)

c#

asp.net-core

sql-server-2005

entity-framework-core

更新