A Quick mysql tutorial in 7394 hours!

@laks wrote:

A Quick mysql tutorial in 7394 hours!

So you are one of those tranditional/rigid user who believe
in SQL and arguing/fighting against NOSQL?

Welcome to a Quick mysql tutorial in 7394 hours!!
(if you don't know mysql and computer and english.)

yeah, recenly conducted bogus scientific research results show
that you'll need approx.7394 hours to complete this tutorial
especially if you don't have any clue about what's mysql and
computer and english!

Lets login to mysql client(use your loginname and database below),


mysql -u yourname -p yourdatabase

Now press Enter key then provide password and see what happens

mysql

Did it say?

Welcome to the MySQL monitor
and more info like mysql version and others?

Now you are logged into interactive mysql prompt.

Lets first create a database: but wait, before that if you don't know what's a
database. Assume database as directory or folder where you store critical
information in a specific format.
you can simply use


create database universe;

will create it.(you can't run create database
command, since we already created one just for
you!..ok..ok..stop clapping your Hands)

Now inorder to use that database; type


use yourdatabasename;


use

Did it say?

Database changed

great!.You are ready to record some
data into this database.

To store information,you must provide
a name and format.This is known as
table. To create a table named 'planets'
type,


create table planets(name varchar(15),position int, has_moon boolean);


Press enter key it should display
Query OK, 0 rows affected

create

Congrats! you successfully created table
with format.

To see list of tables available on this
database type

show tables;


show

Wait a second, let me guess .hmm..

thinking

It should have displayed something like


+-------------------+
| Tables_in_universe|
+-------------------+
| planets |
+-------------------+

right?,yes I know I know , I have IQ 180!
(+ or - 170 :P)

to view the format/structure of this
table.do type,

describe planets;


describe

Did you see the following?

+----------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+----------+-------------+------+-----+---------+-------+
| name | varchar(15) | YES | | NULL | |
| position | int(11) | YES | | NULL | |
| has_moon | tinyint(1) | YES | | NULL | |
+----------+-------------+------+-----+---------+-------+
3 rows in set

This is what we used in create table command
right?If you find anything missing report a
bug to mysql community Image may be NSFW.
Clik here to view.

So we created a 'directory/folder' (read as database)
and 'filename' (read as table) with specfic
'extention' (read as format).Now its time
to 'write' (read as insert) some 'data' (read as record).

Lets first add our home (earth).We know its
at third position from sun and has a moon.

insert into planets values ('earth',3,1);


insert

Now lets add our possible future home,


insert into planets values ('mars',4,2);

mars has 2 moons ! Just take a break, imagine
how is it to live in a place with two moons! Image may be NSFW.
Clik here to view.

yes,that would be cool Image may be NSFW.
Clik here to view.

okay,now we wrote two records into the table.

To retrieve these data from table,type


select * from planets;


select

it shows


+-------+----------+----------+
| name | position | has_moon |
+-------+----------+----------+
| earth | 3 | 1 |
| mars | 4 | 2 |
+-------+----------+----------+


great!
(still dreaming about 2 moons sight? get
back to earth!)

Lets assume,you retrieve only those
record which has only one moon.For this
just append where condition to above
select query.

select * from planets where has_moon=1;

we can modify the above query a little bit more,
we know we are selecting records with has_moon=1,
so ignore that field. show the rest of columns.

select name,position from planets where has_moon=1;

See - Its simple!. Now do

update planet;


update

that should have displayed some error message.

Because you (yes,its you not my fault :P) didn't
tell 'what' column to update and 'where' to
update.

OMG,we entered some wrong data for earth,It appears recently
it moved to 2 place in our solar system! need proof? go
outside at 13:00.So we need to edit that record. How to do
that? Here comes 'update' to your rescue.


update planets set position=2 where name="earth";

Now go and view results again via select query.
Now its time to trash something.Lets delete mars!

Say good bye to "Spirit".We going to destory it.


delete * from planets where name="mars";


delete

RIP Spirit (2003-2013)

Thats it for a short tutorial on mysql!
Stayed tuned for more and play around
with mysql commands.!

Happy learning, No hacking please Image may be NSFW.
Clik here to view.

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