Linq 查询从表中获取最近插入的 Id

Question

I am trying to get the most recently inserted id from the TaskOrder table to use as a hidden field for when I create subtasks. My linq query is below and I am getting an anonymous type error that I can't figure out.

public async Task<int> GetLastTaskOrderId()
{
    var result = (from t in _context.TaskOrder
                  select new
                  {
                     TaskorderId = t.TaskOrderId
                  }).MaxAsync();

    return await result;
}

Answer 1

Try this

public async Task<int> GetLastTaskOrderId()
{
    var item = await _context.TaskOrder.OrderBy(u => u.TaskOrderId).LastOrDefaultAsync();
    return  item.TaskOrderId;
}

or

return  await _context.TaskOrder.MaxAsync(u => u.TaskOrderId); 

I don't know which is faster since the prime key is usually indexed and clustered.