MySQL 13Runningand Shutting down MySQL Server
MySQL 13Runningand Shutting down MySQL ServerFirst check if your MySQL server is running or not. You can use the following command to check it:
ps -ef | grep mysqld
If your MySql is running, then you will seemysqldprocess listed out in your result. If server is not running, then you can start it by using the following command:
Now, if you want to shut down an already running MySQL server, then you can do it by using the following command:
root@host# cd /usr/bin
./mysqladmin -u root -p shutdown
Enter password: ******
Setting Up a MySQL User Account
For adding a new user to MySQL, you just need to add a new entry tothe usertable in the databasemysql.
The following program is an example of adding a new userguestwith SELECT, INSERT and UPDATE privileges with the passwordguest123; the SQL query is:
root@host# mysql -u root -p
Enter password:*******mysql> usemysql;
mysql> INSERT INTO user (host, user, password, select_priv, insert_priv, update_priv)
VALUES (‘localhost’, ‘guest’,
PASSWORD(‘guest123’), ‘Y’, ‘Y’, ‘Y’);
Query OK, 1 row affected (0.20 sec)
mysql> FLUSH PRIVILEGES;
Query OK, 1 row affected (0.01 sec)
mysql> SELECT host, user, password FROM user WHERE user = ‘guest’;
| host | user | password |
| localhost | guest | 6f8c114b58f2ce9e |
1 row in set (0.00 sec)
Notice the FLUSH PRIVILEGES statement. This tells the server to reload the grant tables. If you don’t use it, then you won’t be able to connect to MySQLusing the new user account at least until the server is rebooted.
You can also specify other privileges to a new user by setting the values of following columns in user tableto ‘Y’ when executing the INSERT query or you can update them later using UPDATE query.
Another way of adding user account is by using GRANT SQL command.
root@host# mysql -u root -p password;
mysql> use mysql;
mysql> GRANT SELECT,INSERT,UPDATE,DELETE,CREATE,DROP
-> ON TUTORIALS.*
-> TO ‘zara’@’localhost’
-> IDENTIFIED BY ‘zara123’;
The /etc/my.cnf File Configuration
In most of the cases, you should not touch this file. By default, it will have the following entries:
Here, you can specify a different directory for the error log, otherwise you should not change any entry in this table.
Administrative MySQL Command
USEDatabasename: This will be used to select a databasein the MySQL workarea.
SHOW DATABASES:Lists out the databases that are accessible by the MySQL DBMS.
SHOW TABLES:Shows the tables in the database once a database has been selected with the use command.
SHOW COLUMNS FROMtablename:Shows the attributes, types of attributes, key information, whether NULL is permitted, defaults, and other information for a table.
SHOW INDEX FROMtablename:Presents the details of all indexes on the table, including the PRIMARY KEY.
SHOW TABLE STATUS LIKEtablename\G:Reports details of the MySQL DBMS performance and statistics.