MySQL

Article excerpt from: http://www.cnblogs.com/linjiqin/archive/2013/03/01/2939384.html thanks bo friends to share O (∩_∩) o~MySQL Common commandsMySQL installation directoryDatabase directory/var/lib/mysql/Configuration file/usr/share/mysql

One: MySQL Basic Statement1. Show available databasesshow databases;2. Create a library databaseCreate databaselibrary;3. Using the DatabaseUse library;4. View the tableShow tables;5. Build a Table statementMysql> uselibrary;Database changedMysql>

According to my style, I don't have a diagram.EnvironmentThe following is inspired by Ye Jinlong teachers to explain the relevant environment clearlyThe key parameters for MySQL and Onesql are configured as follows

MySQL Database Common Commands1. mysql Common commandsCreate database name; Create a databaseUse DatabaseName; Select DatabaseDrop database name deletes databases directly and does not alertShow tables; Show TableDescribe TableName; Detailed

All data in reverse chronological orderMysql> SelectId,id_no fromTorderwhere User = 8 Order byCreatetimedesc ;+----+------------------+|Id|Id_no|+----+------------------+| A | 2015072609100000 || at | 2015072816100000 || A | 2015072816100000 ||

SQL model (SQL mode):Restrict user behavior by defining certain rules, and define the corresponding processing mechanism.Common models:AnsiRelaxed mode, check the inserted data, if not conform to the definition type or length, the data type

I know there are three kinds of tables built on the client (I know, I don't know, there are other ways of wood, if you leave a message)1. Right-click a database to create a table, fill in the fields yourself2. Import the. sql file (SQL statement is

Error message MySQL server version for the right syntaxPossible causes 1. The name of the database, the name of the table, the name of the field, cannot appear the MySQL keyword.For example, 1) desc or ASC2) group2. The name of the database, the

1,Xtrabackupinstallation1) Yum installation method:yuminstallhttp://www.percona.com/downloads/percona-release/redhat/0.1-3/percona-release-0.1-3.noarch.rpmYumlist | grep PerconaYuminstall Xtrabackup2) Apt installation method:Apt-keyadv--keyserver

Reprinted from: http://blog.eood.cn/mysql#rd?sukey= Fc78a68049a14bb29c60f21c5254b15a1a9234459cf25ff467de14129ca1193806f26d2b87fb50dec98292d5996d09a7MYSQL should be the most popular WEB back-end database. The WEB development language has recently

Reference article:1.http://www.dotblogs.com.tw/yc421206/archive/2014/03/14/144395.aspxReferring to 1, in VS is already configured, when adding the data entity model, after selecting the MySQL provider, after adding the next, automatically close, no

1, pre-installation of MySQL preparation work(1), download mysql-5.6.21.tar.gz from official website(2), TAR-ZXVF mysql-5.6.21-tar.gz will generate mysql-5.6.21 directory(3), download compressed package cmake-2.8.10.2.tar.gz decompressionTAR-ZXVF

Put the my.cnf on first.[MYSQLD_MULTI]MYSQLD =/usr/bin/mysqld_safemysqladmin =/usr/bin/mysqladminuser =rootpassword =123456[mysqld2]socket =/tmp/mysql.sock2port = 3306pid-file =/home/mysql/mysql2/hostname.pid2datadir =/home/mysql/mysql2user

Constraint type:1, NOT NULL (non-null constraint)2. PRIMARY key (primary KEY constraint)Only one primary key can exist per data tableThe primary key guarantees the uniqueness of the recordPrimary key is not NULL automatically(Auto_increment

1:apache IntroductionApache is the world's top-ranked Web server software, which can run on almost all widely used computer platforms due to its widespread use across platforms and security, is one of the most popular Web server-side software.

the data structures commonly used in indexes are B + trees . The structure is as followsFor example, is a B + tree, the definition of B + tree can be seen in the B + tree, here is only a few points, the light blue block we call a disk block, you can

MySQL noun explanation/meaning mvcc (multiversion concurrency control) The MySQL InnoDB storage engine, which implements the Concurrency Control Protocol--MVCC (Multi-version Concurrency Control) based on multiple versions (note: Compared

A data type is a basic rule that defines what data can be stored in a column and how that data is actually stored. MySQL's common data types include: string Data type : The most commonly used data type, there are two basic types of strings:

MySQL master-slave configurationReplication master-Slave, keep two database data consistentMaster A data changes, generate logs, sent to from b,b According to the log to make corresponding changes, so that the data and A consistent. keeping A,B

MySQL two trick to handle strings: Substring_index,concatI've been dealing with strings in the database lately, and we've found that they're used to go with these two functions:　　1, Substring_index (Str,delim,count)　　STR: The string to be processed