MySQL

MySQL Master-slave Introduction:MySQL master-slave is also called replication, AB replication. Simply speaking is a and b two machines from the back, write the data on a, the other B will follow the writing data, both data real-time

First, MySQL The main application scenarios1. Web Site System2. Logging System3. Data Warehouse System4. Embedded systemSecond, MySQL Frame Composition:Third, MySQL Storage Engine Overview1 ) MyISAM Storage EngineMyISAM Storage Engine table in the

keepalived + haproxy + MySQL build high availability1, the high availability of keepalived is the main preparation, there is a standby2, keepalived + haproxy built high-availability is can be scheduled for two high-availabilityTopology

1. EMS SQL Manager for MySQLis a high-performance MySQL database server System management and development tools. It supports any version from MySQL 3.23 to 6.0 and supports the latest version of MySQL features, including: viewing, storing procedures

Example: SQL fuzzy query, using the like comparison keyword, plus the wildcard characters in SQL, please refer to the following:1, like' mc% 'All strings (such as McBadden) that begin with the letter Mc will be searched.2, like'%iNger 'All strings

DatetimeUsed when you need a value that contains both date and time information. MySQL retrieves and displays the datetime value in ' yyyy-mm-dd HH:MM:SS ' format, supported by ' 1000-01-01 00:00:00 ' to ' 9999-12-31 23:59:59 '. 8 bytes of

Recently, due to the need for work, we began to focus on the relative optimization of select query statements for MySQL databases.Because of the actual project involved, it is found that when the data volume of MySQL table reaches millions, the

Transactions are a very important feature of the database, especially for banks, payment systems, and so on.Database/sql provides the functionality of transaction processing. Implemented by the TX object. Db. Begin creates the TX object, which exec

What is Pymysql?Pymysql is a library used in the python3.x version to connect to the MySQL server, and MySQLdb is used in Python2.Pymysql follows the Python database API v2.0 specification and includes the Pure-python MySQL client library.Pymysql

What is a tableA table is a structured file that can be used to store data of a particular type. A record in the table has a corresponding caption, which is called a table field.　　Two Create a table 12345 CREATE TABLE 表名(字段名1类型[(

I. Overview　　Databases (database, abbreviated DB)Database technology is a very important technology in the field of computer application, it is produced in the the late 1960s, it is the newest technology of data management and also an important

First, the system environment: Centos 6.5 MySQL version: mysql-5.5.25a master:192.168.4.9 slave:192.168.4.10 Second, the principal and subordinate configuration needs attention points Master and Slave server operating

What is a tableA table is a structured file that can be used to store data of a particular type. A record in the table has a corresponding caption, which is called a table field.　　Two Create a table1 CREATE Table table name (2 field name 1 type

Mysqlbinlog:Used to parse Binlog logs. Under the data directory, Mysql.index is the index file for Mysqlbinlog. The role of Binlog is to record internal MySQL deletions. Do not record select.Options:1.-d dbname: For the library, split the binary log

There are two ways to create a primary key: CREATE TABLE Table name (Field Name Type,Field Name Type,......Primary key (name)); or a CREATE TABLE Table name (Field Name Type primary key,Field Name Type,......);

Time functioncurdate () returns the current date Curtime () returns the current time now () returns the current date and time Unix_timestamp (date) Returns the date of the Unix timestamp example: SelectUnix_timestamp ('2017-1-1

In CentOS 7, MariaDB source code package is compiled and installed, and centosmariadb Download the installation package Download the MariaDB 10.2 stable version source code package from the official website. Select source code package After you

Common commands for mysql to authorize, start, and start servicesOne or four startup methods: 1. mysqld Start the mysql server :. /mysqld -- defaults-file =/etc/my. cnf -- user = root client connection: mysql -- defaults-file =/etc/my. cnf or

MySQL transactions and views, MySQL transaction views 　　　　　　　　　　　　　　　　Transactions 1. Concept A set of one or more SQL statements!Transactions: a collection of operations. They are born together. Either the execution is successful or the execution

Python MYsql, database, and pythonmysql Database I. Database Operations and Installation 1. Installation  MySQL Community Server 5.7.16 ---- version 2. Initialization Mysqld-- Inisialize-Insecure 3. Start Mysqld 4,Start the MySQL client and connect