PHP：数组差异; 多维数组和辅助数组键

Question

I am trying to sort out a multidimensional array based on an array of keys (query params), but am having no luck in doing so.

Array From DB:

AOD (Array, 2 elements)
  topic (String, 21 characters ) Alcohol & Other Drugs
  lessons (Array, 29 elements)
CEH (Array, 2 elements)
  topic (String, 25 characters ) Community & Environmental
  lessons (Array, 23 elements)

Array of Keys (Query String):

0 (String, 3 characters ) AOD
1 (String, 3 characters ) CEH

So, if I only passed in AOD, then the first array above would only return the multi-dimensional array of AOD

Code:

array_intersect($snsData, array_flip($query_topics))

Answer 1

Working Code:

array_intersect_key($snsData, array_flip($query_topics))

Where $query_topics is an array of $_GET params