MySQL

Take the example of creating a database with a character set of UTF8:CREATE DATABASE db_name DEFAULT CHARACTER SETUTF8 COLLATE utf8_general_ci;CREATE DATABASEThe syntax:CREATE{DATABASE | SCHEMA}[IF not EXISTS] db_name[create_specification [,

Create a database CREATE DATABASE IF not EXISTS $database DEFAULT CHARSET UTF8 COLLATE utf8_general_ci; CREATE DATABASE $database DEFAULT CHARACTER SET UTF8 COLLATE utf8_general_ci; Create a user and add permissions # just create

Create a test table: MySQL> Create TableBigdata (IDint, nameChar(2) ; Create stored procedure: MySQL>Delimiter//MySQL> Create procedureRand_data (inchNumint) - begin - Declare Str Char( +)default 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0

The following error occurred during the first Test execution: Bigdata There are 1 million data MySQL> Select Count(*) from(Select distinct(ID) fromBigdata) asTotal ; ERROR1317(70100): Query execution was interrupted waited a while and then executed

To count the number of connections to a database, we typically count the totals without subdividing each IP. Now to monitor the number of connections per IP, the implementation is as follows:Method One:Select Substring_index (Host, ': ', 1) as IP,

Scheduled BACKUP Database/usr/sbin/backupmysqltimestamp= ' date + '%y-%m-%d-%h-%m-%s 'Mysqldump-uroot-p ' 123456 databasename>/db$timestamp.sqlchmod +x BackupmysqlInstall Crontab:[email protected] ~]# Yum install Vixie-cron[email protected] ~]# Yum

Method One: Solve garbled problem by adding parameter--default-character-set = UTF8Method One: Solve garbled problem by adding parameter--default-character-set = UTF8Mysql-u root-p Password Method Two: Import garbled address in command lineUse

;CREATE TABLEtabtest (' id 'INT( One) not NULLauto_increment, ' Factora 'VARCHAR(255) not NULL DEFAULT ' ', ' Factorb 'VARCHAR(255) not NULL DEFAULT ' ', ' Factorc 'DECIMAL(Ten,2) not NULL DEFAULT 0, ' remark 'VARCHAR(255) not NULL DEFAULT ' ' ,

Environment: CentOS Linux release 7.1.1503 (Core)1. Install MySQLwget http://dev.mysql.com/get/mysql-community-release-el7-5.noarch.rpmRPM-IVH mysql-community-release-el7-5yuminstall mysql-community-Serverserivce Mysqld StartNow look at the data

When you connect to MySQL using TCP/IP, it appears:Can ' t connect to MySQL server on ' xxx.xxx.xxx.xxx. ' (111)This error.After repeated toss:Determine IP Yes, user rights are available (support remote IP connection), config file to unregister IP

First, start/Shut down the database service:1. Open cmd Command Prompt window2, enter the command net start MySQL , enter, then started the MySQL service3. After entering the command net stop MySQL , enter, then turn off the MySQL serviceSecond, the

Create a database{} Required | Select from front and back [] optionalCreate {database | schema} [if not EXISTS] db_name [default] Character Set [=] Charset_nameCreate a database T1Create DATABASE T1;View all databasesShow database;If not exists (if

Left (outer) Join: The table is the main, which contains all the rows of the left table, and the right table satisfies the recorded data listRight (outer) join: The table that is the main, contains all the rows of the right table, and the left table

One, connect MySQLlocalhost: mysql-h host address-u user name-P user PasswordRemote host: mysql-h host ip-u user name-p user PasswordSecond, change the passwordMysqladmin-u username-p Old password password new passwordThird, create the

MySQL to_days (date) function to_days (date)Given a date , returns a number of days, starting from year 0.Mysql> SELECT to_days (950501);728779Mysql> SELECT to_days (' 1997-10-07′);729669To_days () is not used for values before the Gregorian

Detects if the machine has MySQL installed| grep mysqlAfter executing the above command, you see that the MYSQ socket is in the listening state, indicating that the installation was successful.Install MySQLsudo apt-get install mysql-server

Sub-table strategy1, according to the characteristics of the time table, different days, the time may be uneven, some more, some less, and may appear too large data volume situation2, according to the hash Modulus sub-table (or primary key to mold)

In MySQL's master-slave environment, we can view some of slave's state information by executing the show slave status on Slave, which has a more important parameter seconds_behind_master. So do you understand what it really means and how it's

There are two main types of optimizations for massive data:the way of large table splitting table; optimization of SQL statements Partitioning Technology:similar to horizontal segmentation, but it is a horizontal table at the logical level, which is

Install Mysql and redhatrpm in rpm mode in RedHat 5.8 I want to install Mysql 5.6 ..1. Prepare the file:1) Mysql-client-5.6.24-1.rhel5.x86_64.rpm2) Mysql-server-5.6.24-1.rhel5.x86_64.rpm2. Remove the Mysql version from the system: yum remove mysql*;