How can I confirm if an async EF6 await db.SaveChangesAsync() worked as expected?

Question

My code looks like this:

    public async Task<IHttpActionResult> Delete(int id)
    {
        var userId = Int32.Parse(User.Identity.GetUserId());   
        UserTest userTest = await db.UserTests.FindAsync(id);
        if (userTest == null)
        {
            return NotFound();
        }
        if (userTest.UserId != userId)
        {
            return Unauthorized();
        }
        db.UserTests.Remove(userTest);
        await db.SaveChangesAsync();
        return Ok();
    }

I think everything up to the db.SaveChangesAsync is okay but how can I confirm if the db.SaveChangesAsync works before doing a return Ok() ? Ideally I think I should be checking for exceptions and things but I am not sure how I could fit that into this code block.

Answer 1

From msdn:

public virtual Task<int> SaveChangesAsync()

Return Value Type: System.Threading.Tasks.Task A task that represents the asynchronous save operation. The task result contains the number of objects written to the underlying database.

Check if the result is greater than 0:

if(await db.SaveChangesAsync() > 0)
{
     .....
}

More info here

Another option is to wrap this with try ... catch block:

try
{
    await db.SaveChangesAsync();
    return Ok();
}
catch (Exception ex)
{
    return NotFound(ex.Message);
}