Table: american_idol_season7_auditions
Columns: episode_air_date
audition_city
date
first_audition_venue
callback_date
callback_venue
golden_tickets

Question: Which city had the charleston area convention center as its callback location
SQL: SELECT "audition_city" FROM american_idol_season7_auditions WHERE "callback_venue" = 'Charleston Area Convention Center'

Question: When did the callbacks from  rancho bernardo inn air
SQL: SELECT "episode_air_date" FROM american_idol_season7_auditions WHERE "callback_venue" = 'Rancho Bernardo Inn'