子查詢再多套一層（不過這樣就不支援走索引了，線上環境慎用！）
不支援的寫法：
DELETE FROM your_table WHERE id NOT IN (SELECT id FROM your_table ORDER BY created_at DESC LIMIT 100);
報錯：
1235 - This version of MySQL doesn't yet support 'LIMIT & IN/ALL/ANY/SOME subquery'
支援的寫法：【注意】這樣寫就不支援走索引了
DELETE FROM your_table WHERE id NOT IN (SELECT id FROM (SELECT id FROM your_table ORDER BY created_at DESC LIMIT 100) AS sub_table);
測試：
select * FROM site_info_report_history WHERE id NOT IN (SELECT id FROM site_info_report_history ORDER BY id DESC LIMIT 10000) ORDER BY id DESC; select * FROM site_info_report_history WHERE id NOT IN (SELECT id FROM (SELECT id FROM site_info_report_history ORDER BY id DESC LIMIT 10000) AS sub_table) ORDER BY id DESC;
我這裏的表太大了，直接查資料庫容易崩掉。爲了測試查詢快下面兩個SQL執行時最後加上了LIMIT 1
EXPLAIN看一下，可以看到rows等於資料庫記錄數，Backward index scan，說明沒有走索引，直接全表掃描了，所以線上慎用！
參考：https://blog.csdn.net/weixin_42871288/article/details/121748859
