Last week I looked at how tofind records in a table with MySQL that are not in another tableand this week look at how to delete records in a table with MySQL that are not in another table. Example tables The ex
3 lock struct(s), heap size 360, 2 row lock(s), undo log entries 1 MySQL thread id 1, OS thread handle 0x7f61ab1c7700, query id 134 localhost msandbox cleaning up TABLE LOCK table `test`.`tu` trx id 146751 lock mode IX RECORD LOCKS space id 45 page no 5 n bits 72 index `...
-- 1 Delete 一般是删除表里的数据DELETEFROMtb_userWHEREusername='jack'ORDERBYtimestamp_columnLIMIT1...
DELETE FROM tablename; DELETE * FROM tablename; 1. 2. 3. 4. 5. 6. 7. 删除同一张表内的所有内容 -- Truncate table语句用来删除/截断表里的所有数据 -- 和delete删除所有表数据在逻辑上含义相同,但性能更快 -- 类似执行了drop table和create table两个语句 TRUNCATE tableName; 1. 2. 3. 4. 无...
最近,在脉脉上看到一个楼主提出的问题:MySQL数据量大时,delete操作无法命中索引;并且还附上了相关案例截图。 最终,楼主通过开启MySQL分析优化器追踪,定位到是优化器搞的鬼,它觉得花费时间太长。因为我这个是测试数据,究其原因是因为数据倾斜,导致计算出的数据占比较大、花费时间长。
mysql tables in use 1, locked 1 5 lock struct(s), heap size 1136, 4 row lock(s), undo log entries 2 MySQL thread id 52, OS thread handle 9276, query id 2363 localhost ::1 root update insert into account values(null,'Yan',100) ...
在MySQL中，delete和truncate都是常用的删除数据的方式，但它们之间存在着一些区别。且往下看，万一面试遇到呢？一、delete的用法和示例 delete语句用于删除表中的数据，可以根据条件删除一条或多条数据，语法如下：DELETE FROM table_name WHERE condition;其中，table_name是要删除数据的表名，condition是删除数据的条件...
Delete (slightly duplicated) entries from a table Jake Mitchell June 08, 2007 12:48PM Re: Delete (slightly duplicated) entries from a table laptop alias June 08, 2007 01:34PM Re: Delete (slightly duplicated) entries from a table Jake Mitchell June 08, 2007 03:44PM Re: Del...
mysql tables in use 1, locked 1 LOCK WAIT 18 lock struct(s), heap size 1136, 58 row lock(s), undo log entries 41 MySQL thread id 298, OS thread handle 140425685493504, query id 5479767 172.18.70.114 root updating delete from session where id in (x'B41D1ACB485A4E599A687E4AB1C36648...
MySQL insert 遇到delete 唯一键未提交导致死锁 简介:一 前言死锁,其实是一个很有意思也很有挑战的技术问题,大概每个DBA和部分开发同学都会在工作过程中遇见 。关于死锁我会持续写一个系列的案例分析,希望能够对想了解死锁的朋友有所帮助二案例分析2.1 业务场景用户录入商品,应用程序会提前检查是否存在相同记录,如果有...