Linux Learning CentOS (13) detailed method for installing and configuring MySQL database under--centos6.4 _linux

If you want to do Java EE Development on Linux, first of all, we need to build a Java EE development environment, including the JDK, Tomcat, eclipse installation, if you want to develop Web projects, we can certainly install a myeclipse to the Linux system, This installation method is exactly the same as the installation eclipse, there is no record, with JDK, Tomcat, eclipse we have been able to carry out our program development, but if you want to do a project, even small can not be small projects are inseparable from the data storage AH!!! Yes, we still have one of the most important software not installed, that is, database!!! If there is no database, we do the project is simply utopian, so, for the database installation of this piece, specifically for the installation of MySQL database wrote this essay ...

First, MySQL Introduction

When it comes to databases, most of us think of relational databases, such as MySQL, Oracle, SQL Server, and so on, which are very convenient to install on Windows, and if you want to install the database on Linux, I have to first recommend MySQL database. And the first version of the MySQL database is distributed on Linux systems.

MySQL is a relational database management system, developed by the MySQL AB Company in Sweden and currently belongs to Oracle Company. MySQL is a relational database management system in which the associated database keeps data in different tables rather than putting all the data in a large warehouse, which increases speed and improves flexibility. MySQL's SQL language is the most common standardized language used to access databases. MySQL software uses a dual licensing policy (this term "authorization policy"), it is divided into community and commercial version, because of its small size, speed, the overall cost of ownership, especially the characteristics of open source, the general development of small and medium-sized Web site to choose MySQL as a website database. Thanks to the performance of its community edition, the combination of PHP and Apache can make a good development environment.

Install the MySQL database on Linux, you can download the corresponding database files according to your operating system.

mysql5.0 version Download address collection: http://www.jb51.net/article/39186.htm

Here I am through the yum to the MySQL database installation, this way to install, can be related to MySQL some services, jar bags are installed to us, so save a lot of unnecessary trouble!!!

Second, uninstall the original MySQL

Because the MySQL database is very popular on Linux, so the current download of the mainstream Linux system version is basically integrated with the MySQL database in it, we can use the following command to see if our operating system has been installed MySQL database

[root @ xiaoluo ~] # rpm -qa | grep mysql // This command will check whether the mysql database has been installed on the operating system
If there is, we uninstall it with rpm -e command or rpm -e --nodeps command.

[root @ xiaoluo ~] # rpm -e mysql // Normal delete mode
[root @ xiaoluo ~] # rpm -e --nodeps mysql // Powerful delete mode. If you are prompted to rely on other files when deleting using the above command, you can use this command to perform a powerful delete
After deleting, we can use rpm -qa | grep mysql command to see if mysql has been uninstalled successfully! !!

Third, install mysql through yum

I use yum to install the mysql database. First, we can enter the yum list | grep mysql command to view the downloadable version of the mysql database provided 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 entering the command yum install -y mysql-server mysql mysql-devel (We need to install the mysql-server server)

[root @ xiaoluo ~] # yum install -y mysql-server mysql mysql-deve
After waiting for a while, yum will help us choose the software required to install the mysql database and some other attached software

 We found that installing the mysql database through the yum method saves a lot of unnecessary trouble. When the following results appear, it means that the mysql database installation is successful.
 At this point we can check the version of mysql-server just installed by using 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, go to the mysql official website to download the rpm package and install it. At this point, our mysql database has been installed.

Fourth, the mysql database initialization and related configuration

After we install the mysql database, we will find that there will be an extra mysqld service. This is our database service. We can start our mysql service by entering the service mysqld start command.

Note: If this is the first time we have started the mysql service, the mysql server will first perform the initial 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!

                              [determine]
Starting mysqld: [OK]

At this time, we will see a lot of information after starting the mysql server for the first time, the purpose is to initialize the mysql database. When we restart the mysql service again, we will not be prompted 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 use the chkconfig --list | grep mysqld command to check whether the mysql service starts automatically when it is turned on, 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 start automatically when it is turned on. Of course, we can set it to start by using the chkconfig mysqld on command, so that we do not have to manually start it each time

[root @ xiaoluo ~] # chkconfig mysqld on
[root @ xiaoluo ~] # chkconfig --list | grep mysql
mysqld 0: Disable 1: Disable 2: Enable 3: Enable 4: Enable 5: Enable 6: Disable
After the mysql database is installed, there will only be a root administrator account, but the root account has not yet been set a password for it. When the mysql service is started for the first time, some initialization of the database will be performed. In the message, we see a line like this:

/ usr / bin / mysqladmin -u root password 'new-password' // Set a password for the root account
So we can use this command to set a password for our root account (note: this root account is the mysql root account, not the Linux root account)

[root @ xiaoluo ~] # mysqladmin -u root password 'root' // Use this command to set the root account password to root
At this point we can log in to our mysql database through the mysql -u root -p command

 Five, the main configuration file of the mysql database

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

We can check some information of 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

2./var/lib/mysql Database file storage location of the 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
Total dosage 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 two are the two default database files when the mysql database is installed
srwxrwxrwx. 1 mysql mysql 0 April 6 22:01 mysql.sock
drwx ------. 2 mysql mysql 4096 April 6 21:59 test // These two are the default two database files when the mysql database is installed
We can create a database by ourselves to verify the storage 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
Total dosage 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 ourselves
[root @ xiaoluo mysql] # cd xiaoluo /
[root @ xiaoluo xiaoluo] # ls
db.opt

3./var/log storage location of the mysql database log output

Some log output storage locations of our mysql database are 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 where we store some log information generated by our operations with the mysql database. By viewing this log file, we can get a lot of information

 Because our mysql database is accessible through the network, not a stand-alone version of the database, the protocol used is tcp / ip protocol, we all know that the port number bound to the mysql database is 3306, so we can use the netstat -anp command Let's see if the Linux system is listening on port 3306:
The result is shown above. The 3306 port number monitored by the Linux system is our mysql database! !! !! !!

 This essay details the installation of the mysql database and the basic configuration of the database through yum under CentOS6.4. In the follow-up Linux learning, I will continue to record my experience and experience! !! !! !!