MySQL

1, table operation now the work of creating a table is mostly done using database management tools, although its nature is also used by SQL, but much more convenient. Now let's talk about using SQL statements to manipulate tables. 1.1 The base

I. BACKGROUNDAs the business of the project is constantly running forward, it is inevitable that the amount of database tables will become more and more large, constantly crowding out hard disk space. It is necessary to delete unnecessary data

Server:centos 7.0mysql:5.7.20 MySQL Community Server (GPL)1. Change Password after first login:According to the choice of installation, there are mysqld_safe with Mysqld_safe, no use mysqld. The normal installation should be in the/usr/sbin

First, the installation steps of MySQLTake version 5.7.20 For example:1th Step:2nd Step:3rd Step:4th Step:5th step:6th step:7th step:8th step:9th step:10th Step:11th Step:12th Step:13th Step:14th Step:15th Step:16th Step:17th Step:18th Step:Second,

Order:MySQL installation configuration issues on Windows systems.0x01Go to MySQL's official website to download the MySQL free installation file you want to build. https://dev.mysql.com/downloads/mysql/0x02Unzip the downloaded file. The Data folder

The previous talk about the optimization of MySQL, mainly to build a table for a large number of tables to add indexing mechanism, improve query efficiency, and some simple optimization of SQL statements, after all, I am not a professional database

1. Copy the service file to INIT.D and rename it to MySQLCp/usr/local/mysql/support-files/mysql.server/etc/init.d/mysqld2. Give executable permissionchmod +x/etc/init.d/mysqld3. Add ServiceChkconfig--add mysqld4. Display the list of

See a python exercise online to randomly generate 8-digit coupons, and want to be saved to the MySQL database. I checked the data and wrote the following code to complete this little job.#!/usr/bin/env python# -*- coding: utf-8 -*-#author

One, create the user:Command: CREATE USER ' username ' @ ' host ' identified by ' password ';Description: Username-user name,Host-Specifies the host on which the user can log on, and if localhost is available to the local user, you can use the

1 Modifying table namesRename table AAA to BBB;OrRename table AAA to BBB;2 Modifying the data type of a fieldALTER TABLE person modify name varchar (20);3 modifying field namesALTER TABLE person change stu_name name varchar (25);4 Adding a field

Mysql -- trigger operation, Mysql -- trigger operation1. Why should I use a trigger? 2. Create a trigger 2.1 create a trigger with an execution statement Example: There are two table objects in the database company: The Department table (t_dept)

Database-Mysql, database mysql Let's talk about Mysql today. First, let's talk about itsHistory: Mysql is a relational database management system. It was first developed by MySQL AB in Sweden and later acquired by sun. Later, sun was acquired by

Basic syntax for Mysql database Stored Procedures drop procedure sp_name// Before that, I have told you the basic knowledge of MYSQL syntax. In this article, I will explain the basic syntax knowledge to readers through the code in practice through

EXPLAIN commands and usage in MySQL, and EXPLAIN mysqlexplain 1. Scenario Description: My colleague taught me to use explain in mysql, so I checked the meaning of the returned content. 2. Now the useful content is recorded as follows: 1. explain

Install mysql on centos and set the operation method for remote access. centosmysql 1. Download the mysql repo Source $ Wget http://repo.mysql.com/mysql-community-release-el7-5.noarch.rpm 2. Install the mysql-community-release-el7-5.noarch.rpm

Instance test the enum type of MySQL, instance mysqlenum Some status fields are often encountered during the development project, such as the order status: Pending payment, paid, closed, and refunded, my previous projects used numbers to store these

MySQL database Event scheduled execution task, mysqleventI. background As the business of the Project is constantly moving forward, it is inevitable that the number of tables in the database will become larger and larger, and the hard disk space

Mysql -- index,1. Create and view Indexes Common indexes are created without any restrictions (unique or non-empty ). This type of index can be created on any data type field. (1) create a common index when creating a table Syntax: Example:

Powerdesigner cannot automatically generate comments, To solve the problem that power designer cannot automatically generate comments, only three steps are required: 1. Press the shortcut key Alt + Shift + X to open the Script Editor; 2. Add the

Mysql installation and configuration   I,Configure the MySQL database 1. decompress the green version of mysql and change it to mysql5.7, as shown in figure   Compare versions earlier than 5.6, less data Directories (store data) and my-default.ini