Getting a list within a list, each is a different table in the database

[eluser]Unknown[/eluser]
Thanks for the response thefuzzyone. It is more than one photo per note. I eventually came up with the solution... rather than storing the results of the database query in an object, i stored them in an array. Once I was working in an array I found it easy to step through the array and add a sub-array of photos for each note.

So I have another question if you don't mind! Given that query results can be stored in both arrays and objects, and that in this case it was necessary to use an array:

When would it be necessary to use an object to store the results?