EF Core 中先查询再去更新报错异常解决 The instance of entity type 'xxx' cannot be tracked ...

具体报错：The instance of entity type 'XXXX' cannot be tracked because another instance with the same key value for {'Id'} is already being tracked. When attaching existing entities, ensure that only one entity instance with a given key value is attached. Consider using 'DbContextOptionsBuilder.EnableSensitiveDataLogging' to see the conflicting key values.

解决方案1：查询的时候使用：AsNoTracking()，此时是不带变动跟踪的实体查询。

解决方案2：更新数据时，我们手动去trace一次:EntityState.Detached。