Relational Databases: Difference between revisions
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m (Created page with "== Session 1 == == Session 2 == == Session 3 == == Session 4 == == Session 5 == == Session 6 ==") |
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== |
== General information == |
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== Session 2 == |
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ssh reldb@gks-virt(050-061).scc.kit.edu -p24 |
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== Session 3 == |
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== Session 4 == |
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[[File:agenda.pdf]] |
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== Session 5 == |
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== Session 6 == |
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== Session 1 - Setup == |
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$ mysql -u root |
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mysql> show databases; |
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mysql> create database playground; |
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mysql> show databases; |
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CTRL-D |
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$ sudo ls -la /var/lib/mysql/ |
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$ sudo ls -la /var/lib/mysql/playground |
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$ sudo ls -la /var/lib/mysql/mysql |
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$ mysql -u root |
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mysql> use mysql; |
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mysql> show tables; |
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mysql> select * from user; |
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mysql> create user 'joffrey' identified by 'kings_landing'; |
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mysql> create user 'joffrey'@'localhost' identified by 'kings_landing'; |
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mysql> create user 'hodor' identified by 'hodor'; |
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mysql> create user 'hodor'@'localhost' identified by 'hodor'; |
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mysql> select * from user; |
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mysql> drop user 'joffrey'; |
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mysql> drop user 'hodor'; |
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mysql> select * from user; |
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CTRL-D |
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$ mysql -u hodor -p |
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mysql> use playground; |
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CTRL-D |
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$ mysql -u root |
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mysql> show grants; |
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mysql> grant all privileges on playground.* to 'joffrey'@'localhost'; |
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CTRL-D |
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$ mysql -u joffrey |
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mysql> show grants; |
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CTRL-D |
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== Session 2 - CRUD == |
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$ mysql -u joffrey -p |
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mysql> use playground; |
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mysql> show engines; |
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mysql> create table persons ( |
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name varchar(256), |
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gender char(1) |
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) engine=innodb; |
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mysql> describe persons; |
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mysql> insert into persons (name, gender) values ('Eddard Stark', 'm'); |
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insert into persons (name, gender) values ('Catelyn Stark', 'f'); |
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insert into persons (name, gender) values ('Robb Stark', 'm'); |
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insert into persons (name, gender) values ('Jon Snow', 'm'); |
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insert into persons (name, gender) values ('Arya Stark', 'f'); |
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insert into persons (name, gender) values ('Tywin Lannister', 'm'); |
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insert into persons (name, gender) values ('Cersei Lannister', 'f'); |
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insert into persons (name, gender) values ('Jaime Lannister', 'm'); |
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insert into persons (name, gender) values ('Joffrey Baratheon', 'm'); |
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insert into persons (name, gender) values ('Tyrion Lannister', 'm'); |
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insert into persons (name, gender) values ('Daenerys Targaryen', 'f'); |
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insert into persons (name, gender) values ('Hodor', 'm'); |
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insert into persons (name, gender) values ('Ygritte', 'f'); |
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mysql> select * from persons; |
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mysql> select * from persons where gender='m'; |
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mysql> select gender from persons where name='Hodor'; |
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mysql> select gender, count(*) from persons group by gender; |
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mysql> select * from persons where name like '%Stark'; |
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mysql> select substring_index(name, ' ', 1) from persons; |
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mysql> select substring_index(name, ' ', -1) from persons; |
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mysql> create table persons_2 ( |
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first_name varchar(128), |
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last_name varchar(128), |
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noble_house varchar(128), |
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gender char(1) |
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) engine=innodb; |
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mysql> select substring_index(name, ' ', 1) as first_name, |
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substring_index(name, ' ', -1) as last_name, |
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gender |
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from persons; |
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mysql> insert into persons_2 |
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select substring_index(name, ' ', 1) as first_name, |
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substring_index(name, ' ', -1) as last_name, |
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gender |
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from persons; |
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mysql> insert into persons_2 (first_name, |
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last_name, |
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noble_house, |
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gender) |
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select substring_index(name, ' ', 1) as first_name, |
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substring_index(name, ' ', -1) as last_name, |
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substring_index(name, ' ', -1) as noble_house, |
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gender |
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from persons; |
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mysql> drop table persons; |
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mysql> alter table persons_2 rename persons; |
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mysql> select * from persons; |
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mysql> update persons set noble_house='Stark' where last_name='Snow'; |
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mysql> update persons set noble_house='Lannister' where last_name='Baratheon'; |
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mysql> update persons set last_name=NULL, noble_house=NULL where first_name in ('Hodor', 'Ygritte'); |
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mysql> select first_name from persons where noble_house='Stark' and gender='f'; |
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mysql> select noble_house, count(*) as members from persons group by noble_house order by members desc; |
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mysql> delete from persons where first_name='Joffrey'; |
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== Session 3 - Relations == |
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$ mysql -u joffrey -p |
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mysql> use playground; |
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mysql> create table locations ( |
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name varchar(256), |
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owner varchar(256) |
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) engine=innodb; |
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mysql> insert into locations (name, owner) values ('Winterfell', 'Stark'); |
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insert into locations (name, owner) values ('Casterly Rock', 'Lannister'); |
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insert into locations (name, owner) values ('Kings Landing', 'Targaryen'); |
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insert into locations (name, owner) values ('Nights Watch', 'The Wall'); |
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insert into locations (name, owner) values ('Beyond the Wall', NULL); |
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mysql> select * |
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from persons, locations; |
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mysql> select * |
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from persons p, locations l |
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where p.noble_house = l.owner; |
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mysql> select p.first_name, p.last_name, l.name from persons p, locations l |
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where p.noble_house = l.owner; |
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mysql> select p.first_name, p.last_name, l.name |
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from persons p left join locations l |
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on p.noble_house = l.owner; |
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mysql> select p.first_name, p.last_name, l.name |
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from persons p right join locations l |
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on p.noble_house = l.owner; |
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mysql> select p1.first_name, p2.first_name |
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from persons p1, persons p2 |
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where ((p1.gender='m' and p2.gender='f') |
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and (p1.noble_house != p2.noble_house)); |
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mysql> create table forces ( |
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owner varchar(256), |
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location varchar(256), |
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swordmen int, |
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archers int, |
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catapults int |
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) engine=innodb; |
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mysql> insert into forces (owner, location, swordmen, archers, catapults) values ('Stark', 'Winterfell', 1000, 1000, 10); |
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insert into forces (owner, location, swordmen, archers, catapults) values ('Lannister', 'Casterly Rock', 1000, 1000, 10); |
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insert into forces (owner, location, swordmen, archers, catapults) values ('Targaryen', 'Kings Landing', 1000, 1000, 10); |
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insert into forces (owner, location, swordmen, archers, catapults) values (NULL, 'Beyond the Wall', 1000, 1000, 10); |
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mysql> select * from persons, locations, forces; |
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mysql> select p.noble_house as family, l.name as headquarter, f.location as battlefield, f.swordmen, f.archers, f.catapults |
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from persons p, locations l, forces f |
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where p.noble_house = l.owner |
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and l.owner = f.owner; |
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mysql> select distinct noble_house from persons; |
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mysql> select p.noble_house as family, l.name as headquarter, f.location as battlefield, f.swordmen, f.archers, f.catapults |
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from (select distinct noble_house from persons) p, locations l, forces f |
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where p.noble_house = l.owner |
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and l.owner = f.owner; |
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mysql> insert into forces (owner, location, swordmen, archers, catapults) values ('Stark', 'Casterly Rock', 300, 10, 1); |
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mysql> create view battleground as |
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select p.noble_house as family, l.name as headquarter, f.location as battlefield, f.swordmen, f.archers, f.catapults |
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from (select distinct noble_house from persons) p, locations l, forces f |
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where p.noble_house = l.owner and l.owner = f.owner; |
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mysql> create view noble_houses as |
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select distinct noble_house from persons; |
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mysql> create view battleground as |
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select p.noble_house as family, l.name as headquarter, f.location as battlefield, f.swordmen, f.archers, f.catapults |
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from noble_houses p, locations l, forces f |
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where p.noble_house = l.owner |
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and l.owner = f.owner; |
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mysql> select b1.* |
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from battleground b1, battleground b2 |
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where b1.family != b2.family |
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and b1.battlefield = b2.battlefield; |
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mysql> create view battle as ( |
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select b1.* |
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from battleground b1, battleground b2 |
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where b1.family != b2.family |
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and b1.battlefield = b2.battlefield |
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); |
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mysql> create view strength as |
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select family, swordmen*1+archers*2+catapults*10 as battle_strength |
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from battle; |
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mysql> select * |
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from strength |
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where battle_strength = (select max(battle_strength) |
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from strength); |
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mysql> drop view strength; |
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mysql> drop view battle; |
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mysql> drop view battleground; |
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mysql> drop view noble_houses; |
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== Session 4 - Constraints == |
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$ mysql -u root |
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mysql> SET @@global.sql_mode = "STRICT_ALL_TABLES"; |
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CTRL-D |
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$ mysql -u joffrey -p |
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mysql> use playground; |
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mysql> insert into persons values ('First', 'Last', 'House', 'x'); |
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mysql> insert into persons values ('Second', 'Last', 'House', NULL); |
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mysql> alter table persons modify gender enum('m', 'f'); |
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mysql> select * from persons; |
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mysql> update persons set gender=NULL where gender='x'; |
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mysql> alter table persons modify gender enum('m', 'f'); |
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mysql> delete from persons where gender is null; |
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mysql> alter table persons modify gender enum('m', 'f') not null; |
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mysql> insert into persons values ('First', 'Last', 'House', 'x'); |
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mysql> alter table persons add constraint pk_persons primary key (first_name, last_name); |
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mysql> alter table persons add column id int first; |
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mysql> select * from persons; |
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mysql> alter table persons drop column id; |
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mysql> alter table persons add column id int primary key auto_increment first; |
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mysql> select * from persons; |
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mysql> alter table persons add unique uq_first_last (first_name, last_name); |
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mysql> show create table persons; |
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mysql> alter table locations add constraint pk_locations primary key(name); |
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== Session 5 - Transactions == |
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TERMINAL 0: |
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$ mysql -u root |
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mysql> use playground; |
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mysql> create table tx_test (name varchar(4), age integer) engine=innodb; |
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mysql> insert into tx_test values ('jack', 28); |
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insert into tx_test values ('jill', 25); |
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mysql> select * from tx_test; |
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mysql> select @@global.tx_isolation; |
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mysql> set global transaction isolation level read uncommitted; |
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--- DIRTY READ --- |
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TERMINAL 1: |
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$ mysql -u joffrey -p |
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mysql> use playground; |
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mysql> start transaction; |
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mysql> select age from tx_test where name='jack'; |
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TERMINAL 2: |
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$ mysql -u joffrey -p |
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mysql> use playground; |
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mysql> start transaction; |
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mysql> update tx_test set age=21 where name='jack'; |
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TERMINAL 1: |
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mysql> select age from tx_test where name='jack'; |
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TERMINAL 2: |
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mysql> rollback; |
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CTRL-D |
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--- NON-REPEATABLE READ --- |
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TERMINAL 0: |
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mysql> set global transaction isolation level read committed; |
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TERMINAL 1: |
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mysql> start transaction; |
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mysql> select * from tx_test where name='jack'; |
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TERMINAL 2: |
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mysql> start transaction; |
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mysql> update tx_test set age=29 where name='jack'; |
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mysql> commit; |
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CTRL-D |
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TERMINAL 1: |
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mysql> select * from tx_test where name='jack'; |
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CTRL-D |
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--- PHANTOM READ --- |
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TERMINAL 0: |
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mysql> set global transaction isolation level repeatable read; |
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TERMINAL 1: |
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$ mysql -u joffrey -p |
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mysql> use playground; |
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mysql> start transaction; |
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mysql> select * from tx_test where age between 20 and 30; |
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TERMINAL 2: |
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$ mysql -u joffrey -p |
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mysql> use playground; |
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mysql> start transaction; |
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mysql> insert into tx_test values ('bob', 23); |
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mysql> commit; |
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CTRL-D |
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TERMINAL 1: |
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mysql> select * from tx_test where age between 20 and 30; |
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mysql> commit; |
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mysql> select * from tx_test where age between 20 and 30; |
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CTRL-D |
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--- DEADLOCK --- |
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TERMINAL 0: |
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mysql> alter table tx_test add money integer; |
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mysql> update tx_test set money=100; |
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mysql> delete from tx_test where name='bob'; |
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mysql> set global transaction isolation level read committed; |
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TERMINAL 1: |
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$ mysql -u joffrey -p |
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mysql> use playground; |
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mysql> start transaction; |
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TERMINAL 2: |
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$ mysql -u joffrey -p |
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mysql> use playground; |
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mysql> start transaction; |
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TERMINAL 1: |
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mysql> update tx_test set money=money-50 where name='jack'; |
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TERMINAL 2: |
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mysql> update tx_test set money=money-50 where name='jill'; |
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TERMINAL 1: |
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mysql> update tx_test set money=money+50 where name='jill'; |
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TERMINAL 2: |
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mysql> update tx_test set money=money+50 where name='jack'; |
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TERMINAL 1: |
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mysql> commit; |
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== Session 6 - SQL Injection == |
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$ mysql -u root -p |
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mysql> use playground |
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mysql> create table users (id integer, login varchar(255), password varchar(255)) engine=innodb; |
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mysql> insert into users values (0, 'root', sha(concat('salt', 'hunter2'))); |
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mysql> select * from users where login='root' and password=sha(concat('salt','hunter2')); |
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CTRL-D |
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#!/usr/bin/python |
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import MySQLdb |
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import MySQLdb.cursors |
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session = MySQLdb.connect(host="localhost", |
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user="joffrey", |
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passwd="kings_landing", |
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db="playground", |
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cursorclass = MySQLdb.cursors.SSCursor) |
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cur = session.cursor() |
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login = raw_input('login: ') |
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password = raw_input('password: ') |
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print "select * from users where login=\'%s\' and password=sha(concat('salt', '%s'))" % (login, password) |
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cur.execute("select * from users where login=\'%s\' and password=sha(concat('salt', '%s'))" % (login, password)) |
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if cur.fetchone() is not None: |
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print 'logged in' |
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else: |
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print 'wrong login or password' |
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cur.close() |
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session.close() |
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$ ./inject.py |
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login: root |
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password: ')) or 1=1;# |
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$ ./inject.py |
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login: root |
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password: ')) or 1=1; update users set password=sha(concat('salt','mypass'));# |
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== Session 7 - Indexes == |
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#!/usr/bin/python |
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import random |
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import time |
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import MySQLdb |
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con = MySQLdb.connect(host="localhost", |
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user="joffrey", |
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passwd="kings_landing", |
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db="playground") |
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con.autocommit(True) |
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cur = con.cursor() |
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try: cur.execute('drop table large_table') |
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except: pass |
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cur.execute('create table large_table (l char, s varchar(255), n int) engine=innodb') |
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ts = time.time() |
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for i in xrange(1000000): |
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if i%10 == 0: |
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print i |
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cur.execute("INSERT INTO large_table VALUES ('%s', '%s', %i)" % (chr(random.randrange(65, 91)), |
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''.join([chr(random.randrange(65, 91)) for i in xrange(1,16)]), |
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random.randint(0,1000000))) |
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print 'time taken:', time.time()-ts |
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con.close() |
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$ mysql -u joffrey -p |
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mysql> use playground; |
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mysql> select l, count(*) from large_table group by l; |
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mysql> create index idx_l on large_table(l); |
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mysql> select s, count(*) from large_table where s like 'AB%'; |
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mysql> create index idx_l on large_table(l); |
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mysql> select s, count(*) from large_table where s like 'AB%'; |
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== Session 8 - Partitioning == |
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create table large_table (l char, s varchar(255), n int) engine=innodb |
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partition by range (n) ( |
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partition p0 values less than (500000), |
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partition p1 values less than maxvalue |
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); |
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create table large_table (l char, s varchar(255), n int) engine=innodb |
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partition by hash(n) |
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partitions 10; |
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create table large_table (l char, s varchar(255), n int) engine=innodb |
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partition by list(l) ( |
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partition p0 values in ('A', ... , 'L'), |
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partition p1 values in ('M, ... , 'Z') |
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); |
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== Session 9 - Execution plans == |
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$ mysql -u joffrey -p |
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mysql> use playground |
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mysql> explain <any statement> |
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== Session X - Application development == |
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/* gcc -Wall $(mysql_config --cflags --libs) basic.c -o basic */ |
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#include <stdio.h> |
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#include <stdlib.h> |
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#include <mysql.h> |
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int main() |
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{ |
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MYSQL *con = mysql_init(NULL); |
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MYSQL_RES *cur; |
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MYSQL_ROW row; |
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int cols, i; |
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mysql_real_connect(con, |
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"localhost", |
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"joffrey", |
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"kings_landing", |
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"playground", |
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0, NULL, 0); |
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mysql_query(con, "select * from persons"); |
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cur = mysql_store_result(con); |
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cols = mysql_num_fields(cur); |
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while ((row = mysql_fetch_row(cur))) { |
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for(i = 0; i < cols; i++) { |
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printf("%s ", row[i] ? row[i] : "<NULL>"); |
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} |
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printf("\n"); |
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} |
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mysql_free_result(cur); |
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mysql_close(con); |
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return 0; |
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} |
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#!/usr/bin/python |
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import MySQLdb |
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import MySQLdb.cursors |
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session = MySQLdb.connect(host="localhost", |
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user="joffrey", |
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passwd="kings_landing", |
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db="playground", |
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cursorclass = MySQLdb.cursors.SSCursor) |
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cur = session.cursor() |
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cur.execute('select * from persons') |
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for row in cur.fetchall(): |
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for col in row: |
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print col if col else '<NULL>', |
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print |
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cur.close() |
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session.close() |
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#!/usr/bin/python |
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import MySQLdb |
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import MySQLdb.cursors |
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from multiprocessing import Process |
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from random import randint |
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from time import sleep |
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def get_session(): |
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return MySQLdb.connect(host='localhost', |
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user='joffrey', |
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passwd='kings_landing', |
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db='playground', |
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cursorclass=MySQLdb.cursors.SSCursor) |
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def bootstrap_tables(): |
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cur = get_session().cursor() |
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try: |
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print 'trying to create new table' |
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cur.execute('create table mp_test (value int)') |
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except: |
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print 'table alread existed, truncating instead' |
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cur.execute('truncate table mp_test') |
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cur.close() |
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def insert_rows(): |
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while True: |
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print 'inserting' |
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session = get_session() |
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cur = session.cursor() |
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cur.execute('insert into mp_test values (%s)', randint(0,9)) |
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session.commit() |
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cur.close() |
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session.close() |
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sleep(0.1) |
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def delete_rows(): |
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while True: |
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print 'deleting' |
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session = get_session() |
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cur = session.cursor() |
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cur.execute('delete from mp_test where value = %s', randint(0,9)) |
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session.commit() |
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cur.close() |
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session.close() |
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sleep(0.1) |
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def count_rows(): |
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while True: |
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session = get_session() |
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cur = session.cursor() |
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cur.execute('select count(*) from mp_test') |
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res = cur.fetchone() |
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print 'rows', res[0] |
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cur.close() |
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session.close() |
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sleep(1) |
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if __name__ == '__main__': |
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bootstrap_tables() |
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p_inserter = Process(target=insert_rows) |
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p_deleter = Process(target=delete_rows) |
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p_counter = Process(target=count_rows) |
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p_inserter.start() |
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p_deleter.start() |
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p_counter.start() |
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p_inserter.join() |
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p_deleter.join() |
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p_counter.join() |
Latest revision as of 23:10, 1 September 2014
General information
ssh reldb@gks-virt(050-061).scc.kit.edu -p24
Session 1 - Setup
$ mysql -u root
mysql> show databases; mysql> create database playground; mysql> show databases;
CTRL-D
$ sudo ls -la /var/lib/mysql/ $ sudo ls -la /var/lib/mysql/playground $ sudo ls -la /var/lib/mysql/mysql
$ mysql -u root
mysql> use mysql; mysql> show tables;
mysql> select * from user; mysql> create user 'joffrey' identified by 'kings_landing'; mysql> create user 'joffrey'@'localhost' identified by 'kings_landing'; mysql> create user 'hodor' identified by 'hodor'; mysql> create user 'hodor'@'localhost' identified by 'hodor'; mysql> select * from user;
mysql> drop user 'joffrey'; mysql> drop user 'hodor';
mysql> select * from user;
CTRL-D
$ mysql -u hodor -p
mysql> use playground;
CTRL-D
$ mysql -u root
mysql> show grants; mysql> grant all privileges on playground.* to 'joffrey'@'localhost';
CTRL-D
$ mysql -u joffrey
mysql> show grants;
CTRL-D
Session 2 - CRUD
$ mysql -u joffrey -p
mysql> use playground;
mysql> show engines;
mysql> create table persons ( name varchar(256), gender char(1) ) engine=innodb;
mysql> describe persons;
mysql> insert into persons (name, gender) values ('Eddard Stark', 'm'); insert into persons (name, gender) values ('Catelyn Stark', 'f'); insert into persons (name, gender) values ('Robb Stark', 'm'); insert into persons (name, gender) values ('Jon Snow', 'm'); insert into persons (name, gender) values ('Arya Stark', 'f'); insert into persons (name, gender) values ('Tywin Lannister', 'm'); insert into persons (name, gender) values ('Cersei Lannister', 'f'); insert into persons (name, gender) values ('Jaime Lannister', 'm'); insert into persons (name, gender) values ('Joffrey Baratheon', 'm'); insert into persons (name, gender) values ('Tyrion Lannister', 'm'); insert into persons (name, gender) values ('Daenerys Targaryen', 'f'); insert into persons (name, gender) values ('Hodor', 'm'); insert into persons (name, gender) values ('Ygritte', 'f');
mysql> select * from persons;
mysql> select * from persons where gender='m';
mysql> select gender from persons where name='Hodor';
mysql> select gender, count(*) from persons group by gender;
mysql> select * from persons where name like '%Stark';
mysql> select substring_index(name, ' ', 1) from persons;
mysql> select substring_index(name, ' ', -1) from persons;
mysql> create table persons_2 ( first_name varchar(128), last_name varchar(128), noble_house varchar(128), gender char(1) ) engine=innodb;
mysql> select substring_index(name, ' ', 1) as first_name, substring_index(name, ' ', -1) as last_name, gender from persons;
mysql> insert into persons_2 select substring_index(name, ' ', 1) as first_name, substring_index(name, ' ', -1) as last_name, gender from persons;
mysql> insert into persons_2 (first_name, last_name, noble_house, gender) select substring_index(name, ' ', 1) as first_name, substring_index(name, ' ', -1) as last_name, substring_index(name, ' ', -1) as noble_house, gender from persons;
mysql> drop table persons;
mysql> alter table persons_2 rename persons;
mysql> select * from persons;
mysql> update persons set noble_house='Stark' where last_name='Snow';
mysql> update persons set noble_house='Lannister' where last_name='Baratheon';
mysql> update persons set last_name=NULL, noble_house=NULL where first_name in ('Hodor', 'Ygritte');
mysql> select first_name from persons where noble_house='Stark' and gender='f';
mysql> select noble_house, count(*) as members from persons group by noble_house order by members desc;
mysql> delete from persons where first_name='Joffrey';
Session 3 - Relations
$ mysql -u joffrey -p
mysql> use playground;
mysql> create table locations ( name varchar(256), owner varchar(256) ) engine=innodb;
mysql> insert into locations (name, owner) values ('Winterfell', 'Stark'); insert into locations (name, owner) values ('Casterly Rock', 'Lannister'); insert into locations (name, owner) values ('Kings Landing', 'Targaryen'); insert into locations (name, owner) values ('Nights Watch', 'The Wall'); insert into locations (name, owner) values ('Beyond the Wall', NULL);
mysql> select * from persons, locations;
mysql> select * from persons p, locations l where p.noble_house = l.owner;
mysql> select p.first_name, p.last_name, l.name from persons p, locations l where p.noble_house = l.owner;
mysql> select p.first_name, p.last_name, l.name from persons p left join locations l on p.noble_house = l.owner;
mysql> select p.first_name, p.last_name, l.name from persons p right join locations l on p.noble_house = l.owner;
mysql> select p1.first_name, p2.first_name from persons p1, persons p2 where ((p1.gender='m' and p2.gender='f') and (p1.noble_house != p2.noble_house));
mysql> create table forces ( owner varchar(256), location varchar(256), swordmen int, archers int, catapults int ) engine=innodb;
mysql> insert into forces (owner, location, swordmen, archers, catapults) values ('Stark', 'Winterfell', 1000, 1000, 10); insert into forces (owner, location, swordmen, archers, catapults) values ('Lannister', 'Casterly Rock', 1000, 1000, 10); insert into forces (owner, location, swordmen, archers, catapults) values ('Targaryen', 'Kings Landing', 1000, 1000, 10); insert into forces (owner, location, swordmen, archers, catapults) values (NULL, 'Beyond the Wall', 1000, 1000, 10); mysql> select * from persons, locations, forces;
mysql> select p.noble_house as family, l.name as headquarter, f.location as battlefield, f.swordmen, f.archers, f.catapults from persons p, locations l, forces f where p.noble_house = l.owner and l.owner = f.owner;
mysql> select distinct noble_house from persons;
mysql> select p.noble_house as family, l.name as headquarter, f.location as battlefield, f.swordmen, f.archers, f.catapults from (select distinct noble_house from persons) p, locations l, forces f where p.noble_house = l.owner and l.owner = f.owner;
mysql> insert into forces (owner, location, swordmen, archers, catapults) values ('Stark', 'Casterly Rock', 300, 10, 1);
mysql> create view battleground as select p.noble_house as family, l.name as headquarter, f.location as battlefield, f.swordmen, f.archers, f.catapults from (select distinct noble_house from persons) p, locations l, forces f where p.noble_house = l.owner and l.owner = f.owner;
mysql> create view noble_houses as select distinct noble_house from persons;
mysql> create view battleground as select p.noble_house as family, l.name as headquarter, f.location as battlefield, f.swordmen, f.archers, f.catapults from noble_houses p, locations l, forces f where p.noble_house = l.owner and l.owner = f.owner;
mysql> select b1.* from battleground b1, battleground b2 where b1.family != b2.family and b1.battlefield = b2.battlefield;
mysql> create view battle as ( select b1.* from battleground b1, battleground b2 where b1.family != b2.family and b1.battlefield = b2.battlefield );
mysql> create view strength as select family, swordmen*1+archers*2+catapults*10 as battle_strength from battle;
mysql> select * from strength where battle_strength = (select max(battle_strength) from strength);
mysql> drop view strength;
mysql> drop view battle;
mysql> drop view battleground;
mysql> drop view noble_houses;
Session 4 - Constraints
$ mysql -u root
mysql> SET @@global.sql_mode = "STRICT_ALL_TABLES";
CTRL-D
$ mysql -u joffrey -p
mysql> use playground;
mysql> insert into persons values ('First', 'Last', 'House', 'x'); mysql> insert into persons values ('Second', 'Last', 'House', NULL);
mysql> alter table persons modify gender enum('m', 'f');
mysql> select * from persons;
mysql> update persons set gender=NULL where gender='x';
mysql> alter table persons modify gender enum('m', 'f');
mysql> delete from persons where gender is null;
mysql> alter table persons modify gender enum('m', 'f') not null;
mysql> insert into persons values ('First', 'Last', 'House', 'x');
mysql> alter table persons add constraint pk_persons primary key (first_name, last_name);
mysql> alter table persons add column id int first;
mysql> select * from persons;
mysql> alter table persons drop column id;
mysql> alter table persons add column id int primary key auto_increment first;
mysql> select * from persons;
mysql> alter table persons add unique uq_first_last (first_name, last_name);
mysql> show create table persons;
mysql> alter table locations add constraint pk_locations primary key(name);
Session 5 - Transactions
TERMINAL 0:
$ mysql -u root
mysql> use playground;
mysql> create table tx_test (name varchar(4), age integer) engine=innodb;
mysql> insert into tx_test values ('jack', 28); insert into tx_test values ('jill', 25);
mysql> select * from tx_test;
mysql> select @@global.tx_isolation;
mysql> set global transaction isolation level read uncommitted;
--- DIRTY READ ---
TERMINAL 1:
$ mysql -u joffrey -p
mysql> use playground;
mysql> start transaction;
mysql> select age from tx_test where name='jack';
TERMINAL 2:
$ mysql -u joffrey -p
mysql> use playground;
mysql> start transaction;
mysql> update tx_test set age=21 where name='jack';
TERMINAL 1:
mysql> select age from tx_test where name='jack';
TERMINAL 2:
mysql> rollback;
CTRL-D
--- NON-REPEATABLE READ ---
TERMINAL 0:
mysql> set global transaction isolation level read committed;
TERMINAL 1:
mysql> start transaction;
mysql> select * from tx_test where name='jack';
TERMINAL 2:
mysql> start transaction;
mysql> update tx_test set age=29 where name='jack';
mysql> commit;
CTRL-D
TERMINAL 1:
mysql> select * from tx_test where name='jack';
CTRL-D
--- PHANTOM READ ---
TERMINAL 0:
mysql> set global transaction isolation level repeatable read;
TERMINAL 1:
$ mysql -u joffrey -p
mysql> use playground;
mysql> start transaction;
mysql> select * from tx_test where age between 20 and 30;
TERMINAL 2:
$ mysql -u joffrey -p
mysql> use playground;
mysql> start transaction;
mysql> insert into tx_test values ('bob', 23);
mysql> commit;
CTRL-D
TERMINAL 1:
mysql> select * from tx_test where age between 20 and 30;
mysql> commit;
mysql> select * from tx_test where age between 20 and 30;
CTRL-D
--- DEADLOCK ---
TERMINAL 0:
mysql> alter table tx_test add money integer;
mysql> update tx_test set money=100;
mysql> delete from tx_test where name='bob';
mysql> set global transaction isolation level read committed;
TERMINAL 1:
$ mysql -u joffrey -p
mysql> use playground;
mysql> start transaction;
TERMINAL 2:
$ mysql -u joffrey -p
mysql> use playground;
mysql> start transaction;
TERMINAL 1:
mysql> update tx_test set money=money-50 where name='jack';
TERMINAL 2:
mysql> update tx_test set money=money-50 where name='jill';
TERMINAL 1:
mysql> update tx_test set money=money+50 where name='jill';
TERMINAL 2:
mysql> update tx_test set money=money+50 where name='jack';
TERMINAL 1:
mysql> commit;
Session 6 - SQL Injection
$ mysql -u root -p mysql> use playground mysql> create table users (id integer, login varchar(255), password varchar(255)) engine=innodb; mysql> insert into users values (0, 'root', sha(concat('salt', 'hunter2'))); mysql> select * from users where login='root' and password=sha(concat('salt','hunter2')); CTRL-D
#!/usr/bin/python import MySQLdb import MySQLdb.cursors session = MySQLdb.connect(host="localhost", user="joffrey", passwd="kings_landing", db="playground", cursorclass = MySQLdb.cursors.SSCursor) cur = session.cursor() login = raw_input('login: ') password = raw_input('password: ') print "select * from users where login=\'%s\' and password=sha(concat('salt', '%s'))" % (login, password) cur.execute("select * from users where login=\'%s\' and password=sha(concat('salt', '%s'))" % (login, password)) if cur.fetchone() is not None: print 'logged in' else: print 'wrong login or password' cur.close() session.close()
$ ./inject.py login: root password: ')) or 1=1;# $ ./inject.py login: root password: ')) or 1=1; update users set password=sha(concat('salt','mypass'));#
Session 7 - Indexes
#!/usr/bin/python import random import time import MySQLdb con = MySQLdb.connect(host="localhost", user="joffrey", passwd="kings_landing", db="playground") con.autocommit(True) cur = con.cursor() try: cur.execute('drop table large_table') except: pass cur.execute('create table large_table (l char, s varchar(255), n int) engine=innodb') ts = time.time() for i in xrange(1000000): if i%10 == 0: print i cur.execute("INSERT INTO large_table VALUES ('%s', '%s', %i)" % (chr(random.randrange(65, 91)), .join([chr(random.randrange(65, 91)) for i in xrange(1,16)]), random.randint(0,1000000))) print 'time taken:', time.time()-ts con.close()
$ mysql -u joffrey -p mysql> use playground; mysql> select l, count(*) from large_table group by l; mysql> create index idx_l on large_table(l); mysql> select s, count(*) from large_table where s like 'AB%'; mysql> create index idx_l on large_table(l); mysql> select s, count(*) from large_table where s like 'AB%';
Session 8 - Partitioning
create table large_table (l char, s varchar(255), n int) engine=innodb partition by range (n) ( partition p0 values less than (500000), partition p1 values less than maxvalue );
create table large_table (l char, s varchar(255), n int) engine=innodb partition by hash(n) partitions 10;
create table large_table (l char, s varchar(255), n int) engine=innodb partition by list(l) ( partition p0 values in ('A', ... , 'L'), partition p1 values in ('M, ... , 'Z') );
Session 9 - Execution plans
$ mysql -u joffrey -p mysql> use playground mysql> explain <any statement>
Session X - Application development
/* gcc -Wall $(mysql_config --cflags --libs) basic.c -o basic */ #include <stdio.h> #include <stdlib.h> #include <mysql.h> int main() { MYSQL *con = mysql_init(NULL); MYSQL_RES *cur; MYSQL_ROW row; int cols, i; mysql_real_connect(con, "localhost", "joffrey", "kings_landing", "playground", 0, NULL, 0); mysql_query(con, "select * from persons"); cur = mysql_store_result(con); cols = mysql_num_fields(cur); while ((row = mysql_fetch_row(cur))) { for(i = 0; i < cols; i++) { printf("%s ", row[i] ? row[i] : "<NULL>"); } printf("\n"); } mysql_free_result(cur); mysql_close(con); return 0; }
#!/usr/bin/python import MySQLdb import MySQLdb.cursors session = MySQLdb.connect(host="localhost", user="joffrey", passwd="kings_landing", db="playground", cursorclass = MySQLdb.cursors.SSCursor) cur = session.cursor() cur.execute('select * from persons') for row in cur.fetchall(): for col in row: print col if col else '<NULL>', print cur.close() session.close()
#!/usr/bin/python import MySQLdb import MySQLdb.cursors from multiprocessing import Process from random import randint from time import sleep def get_session(): return MySQLdb.connect(host='localhost', user='joffrey', passwd='kings_landing', db='playground', cursorclass=MySQLdb.cursors.SSCursor) def bootstrap_tables(): cur = get_session().cursor() try: print 'trying to create new table' cur.execute('create table mp_test (value int)') except: print 'table alread existed, truncating instead' cur.execute('truncate table mp_test') cur.close() def insert_rows(): while True: print 'inserting' session = get_session() cur = session.cursor() cur.execute('insert into mp_test values (%s)', randint(0,9)) session.commit() cur.close() session.close() sleep(0.1) def delete_rows(): while True: print 'deleting' session = get_session() cur = session.cursor() cur.execute('delete from mp_test where value = %s', randint(0,9)) session.commit() cur.close() session.close() sleep(0.1) def count_rows(): while True: session = get_session() cur = session.cursor() cur.execute('select count(*) from mp_test') res = cur.fetchone() print 'rows', res[0] cur.close() session.close() sleep(1) if __name__ == '__main__': bootstrap_tables() p_inserter = Process(target=insert_rows) p_deleter = Process(target=delete_rows) p_counter = Process(target=count_rows) p_inserter.start() p_deleter.start() p_counter.start() p_inserter.join() p_deleter.join() p_counter.join()