.Net Core Web API 响应具有多个属性

Question

I am designing an API endpoint and planning to send the response with 2 values ( one with total no of records and second with list of records ) The controller action is designed like below

    [HttpGet]
    [Route("users_bycat")]
    public async Task<ActionResult> GetUsersByCat([FromQuery] int categoryId )
    {       
        var query = db_context.Users.Select(a => a).Where(p => p.CategoryId == categoryId);                   
        var result = await query.ExecuteAsync();

        return Ok(
               new
               {
                   totalRecords = result.Count(),
                   users = result.ToList()
               }
            );
    }

When i am calling this api endpoint, i am getting response like below

    {
        "totalRecords": 37652,
        "users": []
    }

The users array is empty and i try like below, and managed to get the list as response, but i would like to add count as well to the response

    return Ok(  result.ToList());

How can i ensure i will get both totalRecords and users List as a part of response

Answer 1

The ExecuteAsync() is redundant as an IQueryable is materialised upon calling .ToList() . Additionally, calling .Count() will execute an additional database query so it's more efficient to move this call onto the List . The exception to this would be if you were implementing paging.

The below should function as required:

[HttpGet]
[Route("users_bycat")]
public async Task<ActionResult> GetUsersByCat([FromQuery] int categoryId )
{       
    var results = await db_context.Users
      .Where(p => p.CategoryId == categoryId)
      .ToListAsync();
    
    var dto = new
    {
      totalRecords = results.Count,
      users = results
    };

    return Ok(dto);
}