Colleagues, be careful when you use these functions, the difference is just one 'S' at the end of the sentence and makes a huge difference.
If you want to receive just one row from a SQL SELECT command use ExecuteRow (No matter if you use SELECT *) you will receive in the associative array the first selection reached.
But if you want to receive all the records selected in the associative array, you MUST use ExecuteRows (with an S at the end).
I hope this tip will help someone.