How to use the database server

How to use the database server
A MySQL database server for those attending this year's course is installed on the server
All the users are allowed to see all the databases there. A user has all priviledges to those databases
that are called username_database. If your username is xxxx, you can create, change and drop
(delete) databases calles xxxx_bank, xxxx_jobs, xxxx_courses etc.
This is how you work with the system:
You log on to using your normal userID and Unix-password (if you have not
defined a separate password for unix, it is the same as your Windows password). You can use a
communication program such as Putty och ssh Secure Shell, or just sit at one of the computers in
the Linux-class (the penguin class) and use a terminal window. You get one by clicking the right
mouse button and choosing Konsole. Or you can click the F-icon (lower left corner), the choose
Applications, then Utilities, then Terminal. When you have this terminal window, you must use
Linux-commands. You type the commands and push “enter”. Mouse-clicks do not work here. This
is how you connect to babbage:
ssh [email protected]
Inside Åbo Akademi, using our network, it is enought to write
ssh babbage
From home or elsewhere, you must access babbage from First log onto tuxedo
(normal userID, normal password), then write
ssh [email protected]
The computer now asks your password, and you give it the same Windows password. You know
that you are logged onto babbage when the system prompt looks like this:
[[email protected] ~]$ ssh babbage Here I connect to babbage from my own machine called float.
[email protected]'s password:
This is not shown. The cursor does not move. This is how it should be! Just write it! Last login: Tue Feb 22 17:28:32 2011 from
/usr/local/bin/settings: No such file or directory. Never mind this!
[[email protected] ~]$ Here you can see that you are on babbage. The system prompt is the dollar sign $.
When you are on babbage, but not yet running the mysql system, you can e g copy files to your
directory. To copy the file jobdb3.sql that you need for exercise 4, write the following:
$ wget
Note: You must copy these files outside the mysql-system. You cannot do it there!
To get other files from the Swedish course page, you could write e g
$ wget
$ wget
Now you can start the mysql-system:
mysql -u xxxx -p
Replace xxxx above with your own userID, and now give the password that Mats mailed to you or I
gave you. You must write it and push 'enter'; cut and paste won't do! This is how I start mysql (my
userID is soini):
[[email protected] ~]$ mysql -u soini -p
Enter password: Here I write my password - it does not show!
Welcome to the MySQL monitor.
Commands end with ; or \g.
This is important! When you have written the whole query, finish with ';' and push enter.
Your MySQL connection id is 106
Server version: 5.1.54 MySQL Community Server (GPL) by Remi
Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights
reserved.This software comes with ABSOLUTELY NO WARRANTY. This is
free software,and you are welcome to modify and redistribute it
under the GPL v2 license
Type 'help;' or '\h' for help. Type '\c' to clear the current
input statement.
mysql> This is the mysql prompt. After this you can write your query. If the query is long, you
can push 'enter' at any time to get a new line. The query is finished when you write ';' and push
'enter'. Here are some examples:
mysql> show databases;
| Database
| information_schema |
| sakila
| This database you may play with.
| soini_banken
| These are my databases.
| soini_courses
| world
| This database you may play with.
68 rows in set (0.00 sec)
You can create a new database by writing the command
create database xxxx_university; This you only need to do once for each
You choose to use the database by writing
use xxxx_university;
This you must do whenever you wish to use this
You populate (fill in) the database with schemas (university.sql) and data
(university_data_small.sql) by writing
source university.sql;
source university_data_small.sql;
This you only need to do once; then the information stays there if you do not delete it or drop the
The first file has the structure for your database, the second has the contents.
This is how you write a query:
select * from course;
This is how you write a longer query; the '->' prompt is written by the system to let you know that
you can keep on writing. This prompt is shown until you write a ';' and push 'enter':
When you want to use your database next time, simply write
mysql> use soini_university;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> select * push enter
-> from course natural join teaches push enter
-> where ID = 10101 and push enter
-> semester = 'Fall'; push enter
You can drop (delete) your database if you wish - then it is no longer available:
drop database xxxx_university;
Other useful commands are
• show databases; shows you all the databases by all the users
• show tables; shows you which tables there are in the database you use
• describe table_name; to see all the attributes and their descriptions in the table
called table_name
To end your session, write
Don't forget to log out of babbage! And the computer you are currently working