通常单天的日志 仅仅记录当天的日志信息,假设须要查看一月内的日志信息须要对每天的日志表结果集合进行拼接,通经常使用到 union . 储存过程: drop PROCEDURE if EXISTS unionSp; DELIMITER // create procedure unionSp(sTime varchar(32), eTime varchar(32),tchema varchar(32)) begin declare sqlVar varchar(1024000); declare r
MySQL 自4.1版以后开始支持INSERT … ON DUPLICATE KEY UPDATE语法 例如: id name sex age 1 kathy male 23 2 Javer famale 32 3 Mike male 19 方法一: INSERT INTO kk (id, name,sex) VALUES(1,'kara','ssss') ON DUPLICATE KEY UPDATE id=1; 方法二: REPLACE INTO kk(id, name,sex) V
mysql workbench 建表时 - PK: primary key (column is part of a pk) 主键 - NN: not null (column is nullable) 非空 - UQ: unique (column is part of a unique key) 唯一 - AI: auto increment (the column is auto incremented when rows are inserted) 自增 - BIN: binary (i
mysql的日志文件 日志文件大致分为 error log, binary log, query log, slow query log, innodb redo log ;如图: 1.error log the error log file contains information indicating when mysqld was started and stopped also any critical errors that occur while the server is run
MySQL ddl丢表: MySQL server层为了和innodb层保持数据一致性,在写binlog和redo log时,引入了两阶段提交,但不同的变更产生的日志并非都使用这种策略. 下面就来看看ddl语句产生的binlog日志写入交互过程,从源码的角度理解大家熟知的MySQL ddl丢表. 测试: create table mm(id int primary key, name varchar(100)); 注意:测试在MySQL的5.5.18版本.因为dll语句默认提交,所以环境变量