MySQL

To enhance security, MySQL5.7 randomly generates a password for the root user, in error log, about the location of the error log and, if the RPM package is installed, the default is/var/log/mysqld.log.Generally available through Log_error

Recently with friends to build a project, with the Spring+mybatis+mysql.I met a mybatis today. When inserting data into MySQL, Chinese is displayed as '??? ' Problem, take out the next.For the database operation in the Chinese garbled, there are

I. SQL statements1. Split String method:Substring_index (String, ' delimiter ', positive number from left number of several/negative numbers from right to several);For example: Subtring_index (' Aa_bb_cc_dd ', ' _ ', 1);Split into AA BB cc DD,The

The amount of data in a table is 1000W, so when you look at the hard disk space that the table occupies, the data itself is 300M and the index is 200MThis time, delete 500W data, this time the data itself 150M, and the index is still around 200MWhen

Previously felt that there is a long list of error injection, there are various concat (), Rand () and other functions, not easy to remember and use, has not been much careful study. This special study a bit, read some Daniel's summary, get some

1 website Download, link https://www.mysql.com/downloads/Download MySQL Community ServerThe default is for you to choose the Mac OS X platformThe choice is. dmg. Click Download on the right to download.Jump to another interface to indicate that you

Reprinted from: http://369369.blog.51cto.com/319630/790921How to install MySQL database, do not say here, just say its master-slave copy, the steps are as follows:1, the master-slave server for the following actions:1.1. Consistent version1.2.

One server starts multiple MySQL databasesAfter installing MySQLCopy the MySQL database to the current path and rename it to MYSQL2Cp-r/USR/LOCAL/MYSQL/USR/LOCAL/MYSQL2Switch path to MYSQL2Cd/usr/local/mysql2Copy the my.cnf file to

Many times we will be easy to manage the small picture into the database, some people may think this will not cause great pressure on the database, in fact, we can not worry, because I said, is to store some very small pictures, a few k, no

To install the JDK:1. View the system version Uname-a2. View operating system Cat/proc/version3. Upload the installation file to the specified directory TAR-ZXVF jdkxxx.4. Modify the configuration file Vi/etc/profileExport

1 Install the MySQL database and navicat, create the appropriate account (see MySQL installation article)2 Add the appropriate configuration connection information in the Applicationcontext.xml.3. You can import a databaseExport: Select database

ZhuqzLinks: https://www.zhihu.com/question/19719997/answer/81930332Source: KnowCopyright belongs to the author. Commercial reprint please contact the author for authorization, non-commercial reprint please specify the source.Many people's first

 There are three types of MySQL views:merge,temptable,undefined. If there is no algorithm clause, the default algorithm is UNDEFINED(undefined). algorithm can affect How MySQL handles the view. 1,Mergemerges the text of the statement referencing the

Maxscale is one of MariaDB's products, it is easy to implement read/write separation scheme, and provides load balancing and high availability guarantee for read and write separation.First, installation configuration mysql Master and slave,

1. Set the root password (when the root password is empty)Mysqladmin-uroot password "new123";2. Modify MySQL Password (3 methods)1) mysqladmin-uroot-poldboy123 password "new123"; 2) mysql>update Mysql.user set Password=password ("oldboy123") where

The method of creating a user in MySQL is divided into three ways: The method of INSERT user table, the method of create user, and the method of Grant.I. Form of account nameAccount Composition: User name + host (so duplicate user names can appear,

Several possible scenarios and solutions1, may be the/usr/local/mysql/data/mysql.pid file does not have the permission to writeWorkaround: Give permission, execute "chown-r mysql:mysql/var/data" "Chmod-r 755/usr/local/mysql/data" and restart mysqld!2

DROP table if exists news; --Delete if table is presentCREATE TABLE News--Creating tables(ID int unsigned NOT NULL auto_increment,Title varchar (+) NOT null default ' comment ' news headline ',class_id int unsigned NOT NULL default ' 0 ' comment '

Modify by configuration file:Linux Find my.cnf file　　window was modified by looking for My.ini.Sql_mode=no_engine_substitution,strict_trans_tablesModified under normal LinuxConnect the Linux terminal firstVi/etc/my.confIn edit mode, add a line of

This article is reproduced from http://www.linuxidc.com/Linux/2016-07/133128.htm sudo apt-get install Mysql-server Apt-get Isntall mysql-client sudo apt-get install Libmysqlclient-dev During installation, you will be prompted to set a