MySQL

In the MySQL statement we often encounter anti-quotation marks (' '), at the beginning of the time do not know what the meaning, he is what role?It is a symbol that is introduced to differentiate between MySQL's reserved words and ordinary

Build MySQL-based read-write separation tool Amoeba:The Amoeba tool is a tool to realize the MySQL database read/write separation, if it is based on MySQL master-slave replication;Lab environment (Virtual machine):Host role10.10.10.2 Multi-instance

A good memory is better than a bad penThere are three kinds of SQL connection: Inner connection, outer connection, cross connection.Inner connection includes: equivalent connection, non-equivalent connection, natural connectionOuter connection

Reference http://www.cnblogs.com/lakeslove/p/6280404.htmlWith regard to msyql5.7, the biggest change during installation is the default passwordI'm installing MYSQL-5.7.17-MACOS10.12-X86_64.DMG.and

This article is mainly through an experiment to describe, the process is more boring.Experiment PreparationCREATE TABLE Test_lock (ID int auto_increment PRIMARY key, stock int) Engine=innodb;Insert into Test_lock (id,stock) value (1,50);Here I make

After reading the article, it is very enlightening that MySQL is usually the first select when it is update, and at this point, if the index is not used, it will lock the entire table. The best use of indexesBy using the primary key, if we know the

RPM Package Installation method MySQL Uninstall1: Check if the MySQL component is installed.[Email protected] init.d]# Rpm-qa | Grep-i MySQLmysql-devel-5.6.23-1.linux_glibc2.5mysql-client-5.6.23-1.linux_glibc2.5mysql-server-5.6.23-1.linux_glibc2.5As

Move MySQL database directory today on Linux systemsThe configuration is as follows:/etc/my.cnf[Mysqld]Datadir=/home/mysqlSocket=/var/lib/mysql/mysql.sockAfter you change the configuration file, the following issues occur when you restart MySQL110222

In the recent process of building a database, you need to export the MySQL database under the Mac OS System to a. sql file and then import it into MySQL under Windows system. The following steps are summed up in the study:　　One, Mac OS export MySQL

Classification of functions :1, single-line function: For each record input value to calculate, obtains the corresponding calculation result, returns to the user, namely, each record as an input parameter, after the function computation obtains each

Recently, there are many fuzzy queries in the company system, the data volume is large, and the multi-table connection query will affect the performance. So consider using search engines to do all fuzzy query, thinking:MySQL database data

When EF connects to the mysql database to generate an entity model, an error occurs, indicating that the model cannot be generated: "System. Data. StrongTypingException: the value of" IsPrimaryKey "in the" TableDetails "column is DBNull and

Fuzzy query and SQL fuzzy query Public function Index () {// fuzzy query by account, real name, and mobile phone number $ user = M ('cuser'); $ where = "(IFNULL (projectno ,'". session ("user") ['projectno']. "') = '". session ("user") ['projectno'].

MySql SQL optimization tips and mysqlsql tips One day I found that the execution speed of an SQL statement with inner join was not very slow (0.1-0.2), but it did not reach the ideal speed. The two tables are associated, and the associated fields

MySQL sorting by the custom list of specified fields, mysql Field Problem description As we all know, the SQL statements in the ascending order of a field in MySQL are (taking id as an example, the same below ): SELECT * FROM 'mytable'WHERE 'id'

Ultra-simple qps statistical methods (recommended) and qps statistical methods Calculate the QPS value in the last N seconds (including the select and insert values per second) Mysql> select variable_name, sum (per_sec) as qps from (select

InnoDb system architecture and features (Innodb Storage engine Reading Notes summary), innodb Reading Notes Background thread • Master Thread The core background thread is responsible for Asynchronously refreshing the data in the buffer pool to the

Detailed description of Mysql master-slave synchronization configuration practices, detailed description of mysql master-slave practices 1. Introduction I have written an article about the principle of Mysql master-slave synchronization. I believe

How to set the number of mysql connections (Too connections) and mysqlconnections When using mysql, it is found that the number of connections has exceeded ~~~~ [Root @ linux-node1 ~] # Mysql-u glance-h 192.168.1.17-p Enter password: ERROR 1040 (0800

Methods for filtering out certain databases during full mysql backup, mysql backup Filtering Mysql uses the -- all-database parameter for full backup. For example: # Mysqldump-u root-h localhost-p -- all-database>/root/all. SQL When importing data,