Question About Neural Networks

I created a test table (name - "Nset") with the columns:
id (int), n1 (float), n2 (float), n3 (float) and c1 (varchar).
Then filled a table the followings information:
id n1 n2 n3 c1

1 0,1 0,1 0,6 one

2 0,2 0,1 0,5 one

3 0,7 0,5 0,1 two

4 0,4 0,9 0,3 two

5 0,5 0,1 0,5 three

And created a neural network with tuning by default. "id"-field is the key. n1, n2 and n3 are inputs. c1 - predict.

Then i tryed predict query, like:

SELECT

PREDICT([Nset].[c1])

FROM

[Nset]

NATURAL PREDICTION JOIN

(SELECT 0,5 AS [n1], 0,1 AS [n2], 0,5 AS [n3]) AS t

The result is "three". This is correct. And some other tests appeared correct.

But, when I filled the column c1 with numerical values (one = 1, two=2, three=3) and changed type to int, a predict query left off to work correctly.

Previous query return 4.

And other tests showed that a value returned large on unit.

Is this correct?

Thanks.