If your query got more than one result, e.g. you want to get all informations of some pages, this one returns a linear list within the assoc. list with the result. E.g. the query is "Select 'display_name' from '.TABLE_PREFIX.'users" the storrage-array will hold the display_name of the users. Keep in mind that the storrage-array is pass-by-reference, so you will have to declare it first!
$all_names = array(); $database->get_all( "Select 'display_name' from '.TABLE_PREFIX.'users", $all_names );