What is the difference between _id and thread_id?

android

Solution

the `_id` is the primary autoincrement key for the sms `ContentProvider`, the `thread_id` is the id of a particular conversation

Problem

I find there are two fields _id and thread_id in SMS database, What is the difference between _id and thread_id ? If I want to delete a sms by ID, which field should I use? _id or thread_id ? Thanks!

Original source