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Mysql

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Creating MySQL database on Linux system

1. I assume that you are working from your account and not the root. Start a terminal session and become the superuser (Type su at the prompt and then enter the root password).
2. Now we’ll access the MySQL server. Type:

mysql -u root -p

The system prompts for the MySQL root password that you set up in Installing MySQL on Linux. (Note: This is not the Linux root password but the MySQL root password). Enter the password, which is not displayed for security reasons.
Once you are successfully logged in, the system prints a welcome message and displays the mysql prompt … something like

Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 1 to server version: 3.22.32

Type ‘help’ for help.

mysql>

3. Now we are ready for creating the employees database. Issue the command:

create database employees;

(Note: The command ends with a semi-colon)

4. An important point to note is that this database is created by the root and so will not be accessible to any other user unless permitted by the root. Thus, in order to use this database from my account (called manish), I have to set the permissions by issuing the following command:

GRANT ALL ON employees.* TO manish@localhost IDENTIFIED BY “eagle”

The above command grants my account (manish@localhost) all the permissions on employees database and sets my password to eagle. You should replace manish with your user name and choose an appropriate password.
5. Close the mysql session by typing quit at the prompt. Exit from superuser and come back to your account. (Type exit).
6. To connect to MySQL from your account, type:

mysql -u user_name -p

Type in the password when prompted. (This password was set by the GRANTS ALL… command above) . The system displays the welcome message once you have successfully logged on to MySQL. Here is how your session should look like:

[manish@localhost manish]$ mysql -u manish -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 3 to server version: 3.22.32

Type ‘help’ for help.

mysql>

7. Typing the command SHOW DATABASES; will list all the databases available on the system. You should get a display similar to:

mysql> SHOW DATABASES;
+—————-+
| Database |
+—————-+
| employees |
| mysql |
| test |
+—————-+
3 rows in set (0.00 sec)

8. Enter quit at the mysql> prompt to come out of the mysql client program.

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LOAD DUMP

After you have dumped out your data into a file as described here, FTP or scp that dump file to the home directory (/) on our system.

Once you have uploaded the dump file to your account here, get a shell prompt on our system using telnet or ssh.

Now import the dump file into MySQL by typing all the following on 1 single line at the shell prompt:

mysql -p -h DBSERVER dbname < dbname.sql The above assumes that your database name on our system is "dbname" and the dumpfile that you uploaded was named "dbname.sql". Replace those with your correct database name and dumpfile filename. Also replace DBSERVER with your correct database server name. ###### SET OLD PASSWORD Reset the password to pre-4.1 style for each user that needs to use a pre-4.1 client program. This can be done using the SET PASSWORD statement and the OLD_PASSWORD() function: mysql> SET PASSWORD FOR ‘some_user’@’some_host’ = OLD_PASSWORD(‘newpwd’);
mysql> FLUSH PRIVILEGES;

Substitute the password you want to use for “newpwd” in the preceding examples. MySQL cannot tell you what the original password was, so you’ll need to pick a new one.

######
Drop database

Definition: The drop database command is used when you no longer need one of the SQL databases on your server. It will remove it permanently. It is phrased as: drop database [DatabaseName];
Examples: This will remove the database ‘Dresses’ from the MySQL server:

mysql> drop database Dresses;

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