MySQL

The current MySQL website installation tutorial indicates that you can use the Yum method.MySQL YUM RepositoryMySQL Yum library provides rpm installation packages for MySQL clients, servers, and related componentsThe library can also upgrade and

Creating a BAT fileYou need to put 7z.dll and 7z.exe in the bat's sibling directory and Mysqldump.exe these 3 filesEcho offCLSCD/D%~dp0REM===========configure (start) ==============Sethost=127.0.0.1SetUser=AdminSetpass=Configure your MySQL

And the QQ said there are many Martian and emoji expression pictures, these data, if directly insert to MySQL database, general will error, set to UTF8 are not good, must be changed to UTF8MB4 code, the difference between the two see: MySQL utf8mb4

We know the difference between char (m) and varchar (m) is that VARCHAR (m) is a variable-length string, and char (M) is a fixed-length string. For the time being, let's take a look at What is meant by M in CHAR (m) and VARCHAR (m), without regard

First step: Log in to MySQL with your account[[email protected] ~]# mysql-u root or # mysql-uroot-p Step two: change user databasemysql> use MySQLReading table information for completion of table and column namesCan turn off this feature to get a

First create a table:CREATE TABLE INT(all nullDEFAULTnullVARCHAR(20 nullDEFAULTnull)Insert several data:Mysql> Select * fromT1;+------+------+|Id|Name|+------+------+| 1 |Chen|| 2 |Li|| 3 |Huan|+------+------+3Rowsinch

Transferred from: http://codingstandards.iteye.com/blog/604541The sample SQL statements for exporting CSV format data in MySQL are as follows: Select from '/tmp/test.csv', ' " "'"'\ r \ n'The sample SQL statements for importing CSV format data in

View all users in the MySQL databasemysql> SELECT DISTINCT CONCAT (' User: ', user, ' @ ', host, '; ') as query from Mysql.user;To view the permissions of a specific user in a databaseMysql> Show grants for ' cactiuser ' @ '%';Delete UserDelete

When using MySQL, generally try to avoid using keywords as table names, such as using keywords to do table names, you need to write a standard to the SQL statement plus [] (or ") distinguish between the field name and the table name.Here is a list

#!/bin/bash#auto backup MySQL Shell#by Csy 2015-11-11#自动备份数据库, and add a task plan script#定义变量 ===============Bak_cmd=/usr/bin/mysqldumpBak_host=localhostBak_db=csyBak_user=rootBak_pass= "123456"bak_dir=/tmp/mysqlbackup/Bak_date= ' DATE +%f '#环境测试 ..

Problem: When using MySQL, using PHP to insert a database, query database information will be garbled to solve: Modify the MySQL configuration file, in its configuration file added code init_connect= ' SET collation_connection = utf8_ Unicode_ci '

For how to choose the storage engine, can be summed up as a simple sentence: "Unless you need to use some InnoDB features, and there is no other way to replace, otherwise you should choose the InnoDB engine." For example, if you are using a

1 Query TypeThe query type contains:A full table scan, index scans, range scans, unique index lookups, and constants.Const type: Primary key query is generally constAll Type: Full table scan2 Why to split a join operationCaching can is more

ObjectiveIn the database is a sheet of inextricably linked tables, so the table design is good or bad, will directly affect the entire database. While designing the table, we will focus on one issue and what storage engine to use. Wait a minute,

1: Under the terminal: Mysql-v. Here is the code snippet:[Email protected] ~]$ mysql-vMySQL Ver 14.14 distrib 5.5.46, for Debian-linux-gnu (x86_64)2::mysql> status in MySQL;Here is the code snippet:mysql> status;--------------　　MySQL Ver 14.14

The group by syntax can group the results of a query based on each member of a given data column, resulting in a grouped summary table. The column name in the SELECT clause must be a grouping column or a column function. The column function returns

The field type is often null in the database and does not work for statistics count (type) and AVG (type)There are isnull methods in SQL, which are described as follows:ISNULLReplaces NULL with the specified replacement value.GrammarISNULL

1 , install MySQL dependency packageYum install zlib-devel openssl-devel GCC-C++GCC Bison cmake ncurses-devel–y2 , build MySQL user and group, set up MySQL directory for storing data.Groupadd-r MySQLUseradd-g mysql-r-s/sbin/nologin MySQLMkdir–p/data/

The first: Multiple use of the Substring_index () method DELIMITER $$ DROP PROCEDURE IF EXISTS ' array ' $$ CREATE PROCEDURE ' array ' () BEGIN SET @array_content="www mysql com hcymysql blog 51cto com"; SET @i=1; SET

1. Add primary key (primary key index):ALTER TABLE ' table_name ' ADD PRIMARY KEY (' column ')2. Add unique (unique index):ALTER TABLE ' table_name ' ADD UNIQUE (' column ') 3. Add index (normal index):ALTER TABLE ' table_name ' Add index index_name