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This article introduces the "uninstall, installation and configuration of Mysql database in CentOS6.4 system" related knowledge, in the actual case operation process, many people will encounter such a dilemma, then let the editor lead you to learn how to deal with these situations! I hope you can read it carefully and be able to achieve something!

A brief introduction to mysql

MySQL is a relational database management system developed by MySQL AB Company of Sweden and currently belongs to Oracle Company. MySQL is an associated database management system that stores data in different tables instead of all data in a large warehouse, which increases speed and flexibility. MySQL's SQL language is the most commonly used standardized language for accessing databases. MySQL software adopts the double authorization policy (this entry "authorization policy"), which is divided into community version and commercial version. Because of its small size, high speed and low total cost of ownership, especially open source, the development of small and medium-sized websites generally choose MySQL as the website database. Because of the excellent performance of its community version, it can form a good development environment with PHP and Apache.

To install mysql database on Linux, we can download the rpm package of mysql database, http://dev.mysql.com/downloads/mysql/5.6.html#downloads, on its official website. You can download the corresponding database file according to your own operating system. The latest version is 5.6.10.

Here I install the mysql database through yum. By installing in this way, we can install some services and jar packages related to mysql, so it saves us a lot of unnecessary trouble!

2. Uninstall the original mysql

Because mysql database is so popular on Linux, the mainstream Linux system versions currently downloaded basically integrate mysql database in it. We can check whether mysql database has been installed on our operating system by using the following command

[root@xiaoluo ~] # rpm-qa | grep mysql / / this command will check whether the mysql database is installed on the operating system.

If so, we will uninstall it through the rpm-e command or the rpm-e-- nodeps command.

[root@xiaoluo ~] # rpm-e mysql / / normal delete mode

[root@xiaoluo ~] # rpm-e-- nodeps mysql / / forcefully delete mode. If you use the above command to delete other dependent files, you can use this command to delete them.

After the deletion, we can use the rpm-qa | grep mysql command to see if mysql has been uninstalled successfully!

Third, install mysql through yum

I install the mysql database through yum. First, we can enter the yum list | grep mysql command to view the downloadable version of the mysql database available on yum:

[root@xiaoluo ~] # yum list | grep mysql

You can get the downloadable version information of the mysql database on the yum server:

Then we can install mysql mysql-server mysql-devel by typing the yum install-y mysql-server mysql mysql-devel command (Note: when we install mysql, we don't install the mysql client is equivalent to installing the mysql database, we also need to install the mysql-server server)

[root@xiaoluo ~] # yum install-y mysql-server mysql mysql-deve

After waiting for some time, yum will help us choose the software and other ancillary software needed to install the mysql database.

We found that installing the mysql database through yum saves a lot of unnecessary trouble. When the following result appears, it means that the mysql database installation is successful.

At this point, we can view the version of mysql-server that has just been installed with the following command

[root@xiaoluo ~] # rpm-qi mysql-server

The mysql-server we installed is not the latest version. If you want to try the latest version, just go to the mysql website to download the rpm package and install it. Our mysql database has been installed.

IV. Initialization and related configuration of mysql database

After we install the mysql database, we will find that there will be an extra mysqld service, which is our database service, and we can start our mysql service by typing the service mysqld start command.

Note: if this is the first time we start the mysql service, the mysql server will first initialize the configuration, such as:

[root@xiaoluo ~] # service mysqld start

Initialize the MySQL database: WARNING: The host 'xiaoluo' could not be looked up with resolveip.

This probably means that your libc libraries are not 100% compatible

With this binary MySQL version. The MySQL daemon, mysqld, should work

Normally with the exception that host name resolving will not work.

This means that you should use IP addresses instead of hostnames

When specifying MySQL privileges!

Installing MySQL system tables...

OK

Filling help tables...

OK

To start mysqld at boot time you have to copy

Support-files/mysql.server to the right place for your system

PLEASE REMEMBER TO SET A PASSWORD FOR THE MySQL root USER!

To do so, start the server, then issue the following commands:

/ usr/bin/mysqladmin-u root password' new-password'

/ usr/bin/mysqladmin-u root-h xiaoluo password' new-password'

Alternatively you can run:

/ usr/bin/mysql_secure_installation

Which will also give you the option of removing the test

Databases and anonymous user created by default. This is

Strongly recommended for production servers.

See the manual for more instructions.

You can start the MySQL daemon with:

Cd / usr; / usr/bin/mysqld_safe &

You can test the MySQL daemon with mysql-test-run.pl

Cd / usr/mysql-test; perl mysql-test-run.pl

Please report any problems with the / usr/bin/mysqlbug script!

[OK]

Starting mysqld: [OK]

At this time, we will see a lot of information after starting the mysql server for the first time, in order to initialize the mysql database. When we restart the mysql service again, we will not prompt so much information, such as:

[root@xiaoluo ~] # service mysqld restart

Stop mysqld: [OK]

Starting mysqld: [OK]

When we use the mysql database, we have to start the mysqld service first. We can check whether the mysql service starts automatically by using the command chkconfig-- list | grep mysqld, such as:

[root@xiaoluo ~] # chkconfig-- list | grep mysqld

Mysqld 0: close 1: close 2: close 3: close 4: close 5: close 6: close

We found that the mysqld service does not boot automatically. Of course, we can set it to boot by using the chkconfig mysqld on command, so that we don't have to start it manually every time.

[root@xiaoluo ~] # chkconfig mysqld on

[root@xiaoluo ~] # chkconfig-- list | grep mysql

Mysqld 0: off 1: off 2: enable 3: enable 4: enable 5: enable 6: close

After the mysql database is installed, there will only be one root administrator account, but the root account has not yet set a password for it. Some initialization of the database will be carried out when the mysql service is started for the first time. In the long list of information output, we can see the following line of information:

/ usr/bin/mysqladmin-u root password' new-password' / / set the password for the root account

So we can use this command to set a password for our root account (Note: this root account is a mysql root account, not a Linux root account)

[root@xiaoluo ~] # mysqladmin-u root password 'root' / / set the password to the root account as root through this command

At this point, we can log in to our mysql database with the mysql-u root-p command

5. The main configuration files of mysql database

1./etc/my.cnf this is the main configuration file for mysql

We can take a look at some information about this file.

[root@xiaoluo etc] # ls my.cnf

My.cnf

[root@xiaoluo etc] # cat my.cnf

[mysqld]

Datadir=/var/lib/mysql

Socket=/var/lib/mysql/mysql.sock

User=mysql

# Disabling symbolic-links is recommended to prevent assorted security risks

Symbolic-links=0

[mysqld_safe]

Log-error=/var/log/mysqld.log

Pid-file=/var/run/mysqld/mysqld.pid

Database file storage location of 2./ver/lib/mysql mysql database

The database files of our mysql database are usually stored in the / ver/lib/mysql directory

[root@xiaoluo ~] # cd / var/lib/mysql/

[root@xiaoluo mysql] # ls-l

The total dosage is 20488

-rw-rw----. 1 mysql mysql 10485760 April 6 22:01 ibdata1

-rw-rw----. 1 mysql mysql 5242880 April 6 22:01 ib_logfile0

-rw-rw----. 1 mysql mysql 5242880 April 6 21:59 ib_logfile1

Drwx-. 2 mysql mysql 4096 April 6 21:59 mysql / / these are the default database files for mysql database installation

Srwxrwxrwx. 1 mysql mysql 0 April 6 22:01 mysql.sock

Drwx-. 2 mysql mysql 4096 April 6 21:59 test / / these are the default database files for mysql database installation

We can create a database ourselves to verify the location of the database file.

Create our own database:

Mysql > create database xiaoluo

Query OK, 1 row affected (0.00 sec)

[root@xiaoluo mysql] # ls-l

The total dosage is 20492

-rw-rw----. 1 mysql mysql 10485760 April 6 22:01 ibdata1

-rw-rw----. 1 mysql mysql 5242880 April 6 22:01 ib_logfile0

-rw-rw----. 1 mysql mysql 5242880 April 6 21:59 ib_logfile1

Drwx-. 2 mysql mysql 4096 April 6 21:59 mysql

Srwxrwxrwx. 1 mysql mysql 0 April 6 22:01 mysql.sock

Drwx-. 2 mysql mysql 4096 April 6 21:59 test

Drwx-. 2 mysql mysql 4096 April 6 22:15 xiaoluo / / this is the xiaoluo database we just created by ourselves.

[root@xiaoluo mysql] # cd xiaoluo/

[root@xiaoluo xiaoluo] # ls

Db.opt

Log output location of 3./var/log mysql database

Some of the log outputs of our mysql database are stored in the / var/log directory

[root@xiaoluo xiaoluo] # cd

[root@xiaoluo ~] # cd / var/log

[root@xiaoluo log] # ls

Amanda cron maillog-20130331 spice-vdagent.log

Anaconda.ifcfg.log cron-20130331 mcelog spooler

Anaconda.log cups messages spooler-20130331

Anaconda.program.log dirsrv messages-20130331 sssd

Anaconda.storage.log dmesg mysqld.log tallylog

Anaconda.syslog dmesg.old ntpstats tomcat6

Anaconda.xlog dracut.log piranha wpa_supplicant.log

Anaconda.yum.log gdm pm-powersave.log wtmp

Audit httpd ppp Xorg.0.log

Boot.log ibacm.log prelink Xorg.0.log.old

Btmp lastlog sa Xorg.1.log

Btmp-20130401 libvirt samba Xorg.2.log

Cluster luci secure Xorg.9.log

ConsoleKit maillog secure-20130331 yum.log

The mysqld.log file is the log information we store when we operate with the mysql database. By looking at the log file, we can get a lot of information from it.

Because our mysql database can be accessed through the network, it is not a stand-alone database, and the protocol used in it is tcp/ip protocol. We all know that the port number of mysql database binding is 3306, so we can use the netstat-anp command to check whether the Linux system is listening on the port number 3306:

As shown above, the 3306 port number that the Linux system listens to is our mysql database!

This is the end of the tutorial on uninstalling, installing and configuring Mysql Database in CentOS6.4 system. Thank you for reading. If you want to know more about the industry, you can follow the website, the editor will output more high-quality practical articles for you!

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