How to use get_col function

I have this function that uses the get_col function to query a custom table. According to the code I have (see pastebin), am I using get_col correctly?
my table is set up like so:
table: address_table
column: json / contains multi-dimensional array
column: address

I am asking about this because according to this (
get_col returns results in a one-dimensional object.
Since it is a one-dimensional object, would I still use foreach to loop through the JSON results stored in the json table.