android - What is difference between _ID and AUDIO_ID column? -

i've googled it, searched on official android docs, , found nothing satisfying. i'm developing music player app has access media storage , confused between _id , audio_id.

what differences between two? (if any)

following difference.

_id

the unique id row.

audio_id

the id of audio file

difference

_id column name of basecolumns database table. implemented in following other tables.

browser.bookmarkcolumns, browser.searchcolumns, calendarcontract.attendees, calendarcontract.calendaralerts, calendarcontract.calendarentity, calendarcontract.calendars, calendarcontract.colors, calendarcontract.colorscolumns, calendarcontract.events, calendarcontract.eventsentity

and audio_id part of mediastore.audio.audiocolumns, has implementation of basecolumns table.

mediastore.audio.audiocolumns : columns audio file show in multiple tables.

reference : _id , audio_id