MySQL

Original http://blog.csdn.net/goskalrie/article/details/53020631What is a triggerThe trigger (TRIGGER) is one of MySQL's database objects and is supported starting with version 5.0.2. This object is very similar to a function in a programming

LAMP Architecture IntroductionLinux is the operating system Apache is a software that improves Web servicesMySQL is a stored software that saves dataPHP is a scripting languageNote: Apache (httpd) is loaded with PHPPHP is in the form of a module and

From the official website https://dev.mysql.com/downloads/mysql/Download Mysql-5.6.31-winx64.zip, unzip it, the next installation is to install the MySQL database by command. (The version of P.S. 5.7 will be problematic, preferably a 5.6 version)(1)

MySQL numeric functionABS (x) returns the absolute value of XCeil (x) returns the smallest integer value greater than XExample:Select Ceil (0.8), ceil (-0.8); The result is 1, 0Floor (x) returns the maximum integer value less than xExample:Select

First, install the MySQL modulepython2.xPip Install MySQLdbpython3.xPip Install PymysqlSecond, the database connection interfaceBecause Python unifies the interface of the database connection, Pymysql and MySQLdb are similar in the way they are used:

To solve the Mac MySQL forgot the initial password method to share to everyone, for your reference, the specific content as followsThe first step:Click System Preferences, bottom point MySQL, on the popup page, close the serviceStep Two:Enter

1.Table Relationships Note: When you create a table, the length and type of the field are set according to rationality.2. Below: Start your Show1. Check all personnel information2. Only the person's name and age are queried3. Find out who is 20

1. Connect to the databaseTo view available databases, use the show command:SHOW DATABASES;Connect to the database using the use command: use test;Get all tables within the database:SHOW TABLES;To view the table structure: from Test;2. Retrieving

MySQL database uses data types that have Numeric type Integer typeTinyint a tiny integer that occupies 1 bytes by default is the signed integer value range is-128-127 if you need to set an unsigned small integer to be preceded by the

MySQL Master-slave Replication IntroductionIn the current production work, most of the MySQL master-slave synchronization is asynchronous replication mode, that is, not strictly real-time data synchronization.Real-time and asynchronous:    

Very few do not pay attention to the database garbled situation, resulting in character errors:The default is the Latin character set:The table created in this library is also a Latin character set:Insert the normal data below:The display is

MySQL Database service operations# Systemctl Start mysqld//Start# Systemctl Stop mysqld//stop# Systemctl Restall mysqld//restartLog in to MySQL database with a password# mysql-uroot-p ' Initialized random password 'Set User Native login

(1) List all installed RPM package# Rpm-qa | grep mariadbmariadb-libs-5.5.50-1.el7_2.x86_64mariadb-5.5.50-1.el7_2.x86_64mariadb-server-5.5.50-1.el7_2.x86_64(2) Uninstall# RPM-E Mariadb-libs-5.5.50-1.el7_2.x86_64Error at this

Use the MYSQL-E parameter to execute various operation statements of various SQL. Instead of running MySQL at the prompt of MySQL, you can manipulate MySQL in the shell.Format: Mysql-hhostname-pport-uusername-ppassword-e ""　　#!/bin/bashHostname= "192

Optimization of 1.MaxIf there is no index, Max needs to retrieve all the rows to produce the results, which can be optimized by indexing:CREATE INDEX on products (price); Index the price in the Products tableIn this way, querying the maximum value

MySQL basic informationMySQL is an open source relational database implementation. The repository provides images of each version of MySQL, including the 5.6 series, 5.7 series, and so on.How to useThe database is started by default on the 3306 port.

First, IntroductionMySQL's MyISAM storage engine supports compressed table space, the compressed table space will be reduced, but the compressed table is read-only, cannot insert and update data, if need to update, you need to update after

Reprinted from Http://www.cnblogs.com/liuyisai/p/6009379.htmlAmoeba Master profile ($AMOEBA _home/conf/amoeba.xml), which is used to configure the basic parameters of the amoeba service, such as amoeba host address, port, authentication method, user

First, modify the table语法：1. 修改表名 ALTER TABLE 表名 RENAME 新表名;2. 增加字段 ALTER TABLE 表名 ADD 字段名 数据类型 [完整性约束条件…], ADD 字段名 数据类型 [完整性约束条件…]; ALTER TABLE 表名

MySQL operation details and good habits -------- updating..., -------- updating 1. Try not to write too complex SQL queries, and do not think about returning all the results in the form required by the previous end at a time. You can separate the