MySQL

First, the Knowledge reserveDatabase server: One computer (high memory requirements)Database management system: Like MySQL, is a softwareDatabase: Oldboy_stu, equivalent to FolderTable: Student,scholl,class_list, equivalent to a specific fileEntries:

Scenario: Dual master multiple slave db cluster is used when high concurrency and uninterrupted access to the database is requiredExperimental architecture:Lab Environment: Turn off Firewalld and SELinux firewallsOperating system version: CentOS7db1

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:

1. If you want to use a function in a MySQL statement, be sure to remember that there is no space allowed between the function name and the parentheses following it. Having space-time lattices can cause syntax errors.2. If you have entered several

Execute the command mysql_install_dbReferenced from: https://stackoverflow.com/questions/17780630/table-mysql-user-doesnt-existerrormysql -uroot -p 

Yum installationDownload the installation packageCd into yum.repo.d viewClear Bypass, no root privileges .Start mysqldView portsRefresh PasswordChange PasswordSee how many databases you haveView TableVerify the new passwordRPM InstallationDelete

Storage Engine The storage engine is a table type, and MySQL has different processing mechanisms depending on the table type Table is equivalent to a file, a record in the table is equivalent to a row of the file, but a record in the

The on DUPLICATE key update syntax is not a standard syntax for SQL, and if specified at the end of a sentence, it updates the contents of the database according to the specified primary key or uniquely labeled indexThe specific action is to see if

One. Nginx Boot start1. Create a script in the/etc/init.d/directoryVim/etc/init.d/nginx2. Write the contents of the script (copy the following to change the installation path accordingly)#!/bin/bash# nginx Startup script forThe Nginx HTTP server# It

Each storage engine uses three types of locking mechanisms: row-level locking, table-level lock page-level locking. Table-level locking is mainly MyISAM, memory, CSV and other non-transactional storage engines, using row-level locking is mainly the

"1" MySQL configuration file common parameter description：Bind-address:mysql the IP that is bound after the instance is startedPort:mysql the port that is listening after the instance is startedSocket: Socket file path for local socket login to

MySQL variables are divided into three categories.1, global variables (built-in variables): MySQL database built-in variables (all connections play a role) A. See All global variables: show variables; Select @@ 变量 name; Set variable

A view is a virtual table that does not actually store data and stores a "functional relationship."Grammar:CREATE VIEW name as SELECT statement.Why does a view store a function relationship?When referencing a view, it looks for related fields based

MySQL master-slave synchronization principleTransfer from Blog Park-aiapple:http://www.cnblogs.com/aiapple/p/5792939.htmlmaster-Slave formMySQL master-slave replication flexibility One Master one from Primary master replication One

MySQL is a relational database management system developed by the Swedish MySQL AB Company and is currently part of Oracle 's product portfolio. MySQL is one of the most popular relational database management systems, andMySQL is the best in WEB

Principle: MySQL router reads and writes according to the port, sends all requests that connect the read-write port to master, and all requests to the read-only port are polled to multiple slave for read-write separationMaster: Sql-master 192.168.200

Develop a daemon script that monitors MySQL master-slave replication anomalies (including unsynchronized and delayed) every 30 seconds#!/bin/bashfile=/root/mysql.txt #mysql > Show slave status\g; This command can view status information and save it

Select Ifnull (wt.trx_mysql_thread_id,1) blocking_thread_id,t.trx_mysql_thread_id thread_id,CONCAT (P.user, ' @ ', p.host) user,L.lock_table lock_table,L.lock_index Locked_index,L.lock_type Lock_type,L.lock_mode Lock_mode,CONCAT (Floor

Basic mysql operations: Create, view, modify, and delete Databases Related to this section: Create databases, view databases, modify databases, and delete Databases   Start Time:Create a database: Syntax: Create database name [database options];

InnoDB Index, GlossaryClustered index (clustered index) A representation of (primary key) primary key indexes. InnoDB table store is organized based on the primary key column, which can speed up query and sorting. To achieve the best performance, be