MySQL

Knowledge Reserve:1, MySQL has a large number of storage engines, but only a default storage engine, usually it is InnoDB2, MySQL can be sql_mode to control the behavior of MySQL database, today we want to talk about is no_engine_substitution3,

1, left outside the connection to leave outer join, or leaving Jion,outer can be omitted to write, the bottom of the right connection and full connection is the same:The left outer join means that the data in the table on the left side of the right

Http://www.cnblogs.com/digdeep/p/4947694.htmlConsistent reads, also known as snapshot reads. The MVCC mechanism is used to read the data that has been committed in undo. So its read is non-blocking.Related documents: http://dev.mysql.com/doc/refman/5

The   unix_timestamp function can accept a parameter, or it can not use a parameter. Its return value is an unsigned integer. Without parameters, it returns the number of seconds since January 1, 1970 0:0 0 seconds to now, and if parameters are used,

Show TRIGGERS; View all triggersCreate Trigger TG1After insert on userFor each rowBeginUpdate user set Name= ' test ' where id=1;EndInsert into User (Name,pass) VALUES (' Shao ', ' 23 ') $$CREATE Trigger SyntaxCREATE TRIGGER trigger_name

Background Mysql/innodb's locking analysis has been a difficult topic. In the course of my work, my colleagues have often consulted on this issue. At the same time, the micro-blog also often receive the MySQL lock-related private messages, let

Issue 1: Just installed MySQL, set the user name password root, login OK, and then even how can not even on theOperation Steps:Input: Mysql-uroot-prootTip: ERROR 1045 (28000): Access denied for user ' root ' @ ' localhost ' (using

Thank you for sharing:http://blog.itpub.net/13379967/viewspace-715701/  sometimes it is often necessary to group intervals in statistical requirements  mysql can use ELT functions to achieve such requirements  mysql> SELECT * FROM k1;+------+------+|

MySQL Slow query settingsThe method of analyzing the performance of MySQL statement query in addition to using the EXPLAIN output execution plan, you can also let the MySQL record query over a specified time of the statement, we will exceed the

Navicat for MySQL provides users with complete user-defined interface options, from the main menu to select Tools---options, but many users first contact, how to set this aspect is not very understanding, this tutorial will be detailed to introduce

1. SQL Statement ClassificationDDL data Definition Language: Create/drop/alterDML data manipulation statement: Insert/delete/update/truncateDQL data Query Language: select/show2. Data constraint2.1. What are data constraintsTo constrain column value

1. New Project2. Create a folder for the class Dal3. Create related classes"Student Class"Using System;Using System.Collections.Generic;Using System.Linq;Using System.Text;Using System.Threading.Tasks;Namespace ETTest3{public class Student{public

Introduction Xtrabackup is a MySQL database backup tool provided by Percona, officially described, which is the world's only one by one open source tools that enable hot provisioning of InnoDB and XTRADB databases. Characteristics:(1) The backup

Introduction to a custom function (1) Custom function definition The user-defined function (user-defined function,udf) is a way to extend the MySQL database using the same usage as built-in functions. (2) Two necessary conditions for a custom

Installing MySQL on Linux sometimes appears [Mysql]error 2002 (HY000): Can ' t connect to local MySQL server through socket '/var/lib/mysql/mysql.so CK ' (2) Such a mistake, the specific solution is as follows:[Email protected] ~]#

1. BackgroundMysql/innodb's locking analysis has been a difficult topic. In the course of my work, my colleagues have often consulted on this issue. At the same time, the micro-blog also often receive the MySQL lock-related private messages, let me

1, installing DBD perl-io-socket-ssl percona-toolkitYum list|grep dbdyum list|grep socket|grep SSL yum-y install perl-dbd-mysql.x86_64yum-y install Perl-io-socket-ssl.noarc Hyum-y Install "Perl (term::readkey)" Wget https://www.percona.com/downloads/

Today the production server MySQL appeared a not too unfamiliar error "Too many connections". I usually encounter this problem, I basically modify the/etc/my.cnf max_connections parameter, and then restart the database. ButThe database on the

1. Working logic diagram 650) this.width=650; "Src=" http://192.168.1.195:8090/download/attachments/524471/22542025026.jpeg?version=1& Modificationdate=1446626151000&api=v2 "/> 2, mysql-mmm advantages and disadvantages Advantages: High availability,

How to install and configure mysql5.6: graphic tutorial, how to install and configure mysql5.6 I also learned python from scratch. However, when I have just processed the data, I need to use a database to store the data. So I have to configure the