* select * from `test_users` where exists
* (
* select * from `test_user_profiles`
* where `test_users`.`id` = `test_user_profiles`.`user_id`
* )
优化版
* select * from `test_users` where `test_users`.`id` in
* (
* select `test_user_profiles`.`user_id` from `test_user_profiles`
* where `test_users`.`id` = `test_user_profiles`.`user_id`
* )