CS 461: Database Systems. Midterm review. Julia Stoyanovich

Transcription

1 CS 461: Database Systems Midterm review Julia Stoyanovich

2 Sets Let us denote by M the set of all musicians, by R the set of rock musicians, by B the set of blues musicians, by G the set of musicians that won a Grammy award, and by V the set of musicians who won an MTV Video Music Award (VMA). (a) Blues musicians who won both a Grammy and a VMA. (b) Grammy-winning musicians whose genre is neither blues nor rock. (c) Musicians who won a VMA but not a Grammy, and whose genre is not rock. 2

3 Sets Let us denote by M the set of all musicians, by R the set of rock musicians, by B the set of blues musicians, by G the set of musicians that won a Grammy award, and by V the set of musicians who won an MTV Video Music Award (VMA). (a) Blues musicians who won both a Grammy and a VMA. B G V (b) Grammy-winning musicians whose genre is neither blues nor rock. G B R (c) Musicians who a VMA but not a Grammy, and whose genre is not rock. V G R 3

4 Sets Let us denote by M the set of all musicians, by R the set of rock musicians, by B the set of blues musicians, by G the set of musicians that won a Grammy award, and by V the set of musicians who won an MTV Video Music Award (VMA). (d) Grammy-winning musicians whose genre is either rock or blues but not both. (e) The number of pairs of musicians in which the first musician is a Grammywinning rock musician, and the second is a blues musician. 4

5 Sets Let us denote by M the set of all musicians, by R the set of rock musicians, by B the set of blues musicians, by G the set of musicians that won a Grammy award, and by V the set of musicians who won an MTV Video Music Award (VMA). (d) Grammy-winning musicians whose genre is either rock or blues but not both. G (R B) (R B) (e) The number of pairs of musicians in which the first musician is a Grammywinning rock musician, and the second is a blues musician. (G R) B 5

6 ER modeling Each musician who records at the studio has a social security number (SSN), a name, an address, and a phone number, and no two musicians have the same SSN. Poorly paid musicians often share the same address. Each musician has exactly one address and at least one phone number. Producers have a name and an SSN. No two producers have the same SSN. Albums are described by a title and a recording year, and no two albums have the same combination of title and year. Each album is recorded by one or several musicians. Each album has exactly one producer, and each producer produces at least one album. 6

7 ER modeling Each musician who records at the studio has a social security number (SSN), a name, an address, and a phone number, and no two musicians have the same SSN. Poorly paid musicians often share the same address. Each musician has exactly one address and at least one phone number. Producers have a name and an SSN. No two producers have the same SSN. Albums are described by a title and a recording year, and no two albums have the same combination of title and year. Each album is recorded by one or several musicians. Each album has exactly one producer, and each producer produces at least one album. 7

8 ER modeling Each musician who records at the studio has a social security number (SSN) and a name, and no two musicians have the same SSN. Musicians form bands. A band is described by a unique name and has at least two musicians as members. Bands record albums, which have a title, a genre, and a year of production. Each album is recorded by at least one band, and no two albums have the same combination of title and production year. Some musicians produce albums. Each album is produced by at least one musician. (Don t worry about whether that musician is a member of the recording band.) Albums are made up of songs. Each song is assigned a title and a sequence number. You may assume that, if the studio no longer wants to store information about an album, then it also does not store the songs belonging to that album. Naturally, each song belongs to exactly one album, and all songs on the same album have different sequence numbers. 8

9 ER modeling Each musician who records at the studio has a social security number (SSN) and a name, and no two musicians have the same SSN. Musicians form bands. A band is described by a unique name and has at least two musicians as members. Bands record albums, which have a title, a genre, and a year of production. Each album is recorded by at least one band, and no two albums have the same combination of title and production year. Some musicians produce albums. Each album is produced by at least one musician. (Don t worry about whether that musician is a member of the recording band.) Albums are made up of songs. Each song is assigned a title and a sequence number. You may assume that, if the studio no longer wants to store information about an album, then it also does not store the songs belonging to that album. Naturally, each song belongs to exactly one album, and all songs on the same album have different sequence numbers. 9

10 ER modeling An athlete has a name and a date of birth (DOB), and no two athletes have the same combination of name and DOB. A team is described by a name, and no two teams have the same name. A sport is described by a name, and contains information about whether it is an Olympic sport or not. All sports have different names. Each athlete plays at least one sport, and belongs to at most one team. Each team is made up of at least two athletes. 10

11 ER modeling An athlete has a name and a date of birth (DOB), and no two athletes have the same combination of name and DOB. A team is described by a name, and no two teams have the same name. A sport is described by a name, and contains information about whether it is an Olympic sport or not. All sports have different names. Each athlete plays at least one sport, and belongs to at most one team. Each team is made up of at least two athletes. 11

12 Relational to ER create table This ( B integer primary key create table That ( A integer primary key, B integer unique not null, C integer, foreign key (B) references This (B) create table Other ( A integer primary key, D integer not null, foreign key (A) references That (A) 12

13 Relational to ER create table This ( B integer primary key create table That ( A integer primary key, B integer unique not null, C integer, foreign key (B) references This (B) create table Other ( A integer primary key, D integer not null, foreign key (A) references That (A) 13

14 ER to relational 14

15 ER to relational create table This ( A integer, B integer, primary key (A, B) create table That ( C integer primary key, D integer, A integer not null, B integer not null, unique (A, B) foreign key (A, B) references This (A, B) 15

16 ER to relational name) field) DOB) num) 7tle) INVENTORS) have) PATENTS) name) country) posi7on) work)at) INSTITUTES) 16

17 ER to relational name) field) DOB) num) 7tle) INVENTORS) have) PATENTS) name) country) posi7on) work)at) INSTITUTES) create table Institutes ( name varchar(128) primary key, country varchar(64) create table Patents { inventor_name varchar(128), create table Inventors ( num integer, name varchar(128) primary key, title varchar(128), field varchar(128), primary key (inventor_name, num), DOB date, foreign key (inventor_name) institute_name varchar(128) not null, references Inventors(name) position varchar(64), on delete cascade foreign key (institute_name) references Institutes(name) 17

18 ER to relational name) party) name) PRESIDENT) running_mate) VICE_PRESIDENT) start) end) TERM) 18

19 ER to relational name) party) name) PRESIDENT) running_mate) VICE_PRESIDENT) start) end) TERM) create table All_In_One ( president_name varchar(128) primary key, VP_name varchar(128) not null, term_start date not null, term_end date not null, party varchar(64), unique (VP_name), unique (term_start, term_end), 19

20 ER modeling An author is described by a name and a date of birth (dob). No two authors have the same combination of name and dob. A book is described by an ISBN, a title and a year when it was written (year). No two books have the same ISBN number. A book is written by exactly one author. An author is only included in the database is she has authored at least one book. 20

21 ER modeling An author is described by a name and a date of birth (dob). No two authors have the same combination of name and dob. A book is described by an ISBN, a title and a year when it was written (year). No two books have the same ISBN number. A book is written by exactly one author. An author is only included in the database is she has authored at least one book. 21

22 ER modeling A scientist is described by a name, a field of study, and a date of birth (dob). No two scientists have the same combination of name and dob. A discovery has a name. No two discoveries have the same name. An award has a name, which uniquely identifies it. Scientists make discoveries. A discovery is made by one or several scientists. A scientist who made no discoveries is not tracked in our database. Scientists receive awards. A scientist may receive the same award more than once in different years. All years in which a scientist received a particular award must be recorded. 22

23 ER modeling A scientist is described by a name, a field of study, and a date of birth (dob). No two scientists have the same combination of name and dob. A discovery has a name. No two discoveries have the same name. An award has a name, which uniquely identifies it. Scientists make discoveries. A discovery is made by one or several scientists. A scientist who made no discoveries is not tracked in our database. Scientists receive awards. A scientist may receive the same award more than once in different years. All years in which a scientist received a particular award must be recorded. 23

24 ER to relational 24

25 ER to relational create table Chefs ( ssn char(9) primary key, name varchar(128), work_at_name varchar(128) not null, work_at_city varchar(128) not null, own_name varchar(128), own_city varchar(128), create table Restaurants ( name varchar(128), city varchar(128), primary key (name, city) foreign key (works_at_name, works_at_city) references Restaurants (name, city), foreign key (owns_name, owns_city) references Restaurants (name, city) 25

26 ER to relational 26

27 ER to relational create table Satellites_Orbit_Planets ( sat_name varchar(128) unique, sat_mass integer, panet_name varchar(128) primary key, planet_mass integer another option? 27

28 HW 2 Problem 1(a) create table A ( id integer primary key, name char(32) create table B ( id integer primary key, name char(32) create table C_rel ( id integer primary key, name char(32), a_id integer unique not null, b_id integer not null, foreign key (a_id) references A(id), foreign key (b_id) references B(id), 28

29 HW 2 Problem 1(b) create table A_rel1 ( id integer primary key, name char(32), b_id integer, foreign key (b_id) references B(id) create table B ( id integer primary key, name char(32) create table C_rel2 ( id integer primary key, name char(32), b_id integer not null, foreign key (b_id) references B(id), 29

30 HW 2 Problem 2(a) create table Foo ( X integer primary key, Y integer unique, Z integer not null, foreign key (Y) references Bar(Y) create table Bar ( Y integer primary key create table Baz ( X integer primary key, W integer not null, foreign key (X) references Foo(X) 30

31 HW 2 Problem 2(b) create table R ( rid integer primary key, create table T ( name varchar(64) not null tid integer primary key, ) val float, sid integer, create table S ( foreign key (sid) references S(sid) sid integer primary key, ) name varchar(64) not null, rid integer not null unique, foreign key (rid) references R(rid) ) 31

32 HW 3 Problem 3(a) name% isolympic% name% dob% play& SPORTS& ATHLETES& name% belong_to& TEAMS& create table Sports ( name varchar(64) primary key, isolympic boolean create table Teams ( name varchar(64) primary key create table Athletes ( name varchar(64), dob date, team varchar(64), sport varchar(64) not null, primary key (name, dob), foreign key (team) references Teams(name), foreign key (sport) references Sports(name) 32

33 HW 3 Problem 3(b) create table Galleries ( name varchar(128), city varchar(128), primary key (name, city) create table Display ( title varchar(128), author varchar(128), gname varchar(128, gcity varchar(128, primary key (title, author, gname, gcity), create table Paintings_Own ( foreign key (title, author) title varchar(128), references Paintings_Own (title, author), author varchar(128), foreign key (gname, gcity) gname varchar(128) not null, references Galleries (name, city) gcity varchar(128) not null, primary key (title, author), foreign key (gname, gcity) references Galleries (name, city) 33

34 HW 3 Problem 3(c) create table Airlines ( name varchar(32), country varchar(32), primary key (name, country) create table Flights ( num varchar(32) primary key, dept date, arr date, aname varchar(32), acountry varchar(32), foreign key (aname, acountry) references Airlines (name, country) create table Cities ( name varchar(32), country varchar(32), population integer, primary key (name, country) create table Connect ( flight_num varchar(32), orig_city varchar(32), orig_country varchar(32), dest_city varchar(32), dest_country varchar(32), primary key (flight_num, orig_city, orig_country, dest_city, dest_country), foreign key (fight_num) references Flights(num), foreign key (orig_city, orig_country) references Cities (name, country), foreign key (dest_city, dest_country) references Cities (name, country) 34

35 HW 3 Problem 3(d) name diameter mass Planets name Satellites orbit orbital_period create table Satellites ( name varchar(64), planet varchar(64), orbital_period integer, primary key (name, planet), foreign key (planet) references Planets(name) on delete cascade period orbit named after name brightness name mythology Stars metallicity Deities create table Deities ( name varchar(64), mythology varchar(64), primary key (name, mythology) create table Stars ( name varchar(64) primary key, brightness integer, metallicity integer create table Planets ( name varchar(64) primary key, diameter integer, mass integer, star varchar(64) not null, period integer, deity varchar(64), mythology varchar(64), foreign key (star) references Stars(name), foreign key (deity, mythology) references Deities (name, mythology) 35