EF 部分更新 忽略NULL

//全部更新
public T Update<T>(T entity) where T : ModelBase
{
    var set = this.Set<T>();
    set.Attach(entity);
    this.Entry<T>(entity).State = EntityState.Modified;
    this.SaveChanges();
    return entity;
}

//全部更新，忽略NULL字段
public T Update2<T>(T entity) where T : ModelBase
{
    var set = this.Set<T>();
    set.Attach(entity);
    foreach (System.Reflection.PropertyInfo p in entity.GetType().GetProperties())
    {
        if (p.GetValue(entity) != null)
        {
            this.Entry<T>(entity).Property(p.Name).IsModified = true;
        }
    }
    this.SaveChanges();
    return entity;
}

//部分更新，propNames为需要更新的字段
public void Update(T entity, string[] propNames)
{
   
    var oldEntity = _masterContext.Attach(entity);//告诉EF entity，因为调用DbContext.Attach方法后，EF Core会将entity实体的State值（可以通过testDBContext.Entry(person).State查看到）更改回EntityState.Unchanged
    foreach (var prop in propNames)
    {
        oldEntity.Property(prop).IsModified = true;
    }
    _masterContext.SaveChanges();
}