1 r. ching, ph.d. mis dept. california state university, sacramento week 4 september 19 relational...

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R. Ching, Ph.D. • MIS Dept. • California State University, Sacramento

Week 4Week 4September 19September 19

• Relational Data ModelRelational Data Model• ViewsViews

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CriteriaCriteria

Relational ModelRelational Model

• ObjectivesObjectives

– A degree of data independenceA degree of data independence

– Address data semantic, consistency and redundancy Address data semantic, consistency and redundancy problemsproblems

– Set-oriented data manipulation languageSet-oriented data manipulation language

• Structured Query Language (SQL)Structured Query Language (SQL)

Data SetData Set

Presen-Presen-tation tation methodmethod

DatabaseDatabase

InformationInformation

3


Data SetData Set



Data SetData Set


Data SetData Set


DatabaseDatabase

CriteriaCriteria

Crit

eria

Crit

eria

Criteria

Criteria



4


Tuples Tuples (rows)(rows)• CardinalitiyCardinalitiy = =

number of number of tuplestuples

RelationRelation

AttributesAttributes (columns) (columns)• Degree of a relation = number of attributesDegree of a relation = number of attributes

Attrib

ute-

1

Attrib

ute-

1Attr

ibut

e-2

Attrib

ute-

2

Attrib

ute-

n

Attrib

ute-

n

EntityEntity

Domain = all values an attribute can assumeDomain = all values an attribute can assume

5


Domain of an AttributeDomain of an Attribute

• Set of allowable values for one or more attributesSet of allowable values for one or more attributes

DomainDomain DomainDomainUnionUnion

ororIntersectionIntersection


Attribute 1Attribute 1 Attribute 2Attribute 2

6


Properties of RelationsProperties of Relations

• Distinct (i.e., unique) relation nameDistinct (i.e., unique) relation name

• Each cell contains exactly one atomic (single) value Each cell contains exactly one atomic (single) value

– No repeating groupsNo repeating groups

• Distinct attribute nameDistinct attribute name

• The values of an attribute come from the same domainThe values of an attribute come from the same domain

• Order of attributes has no significanceOrder of attributes has no significance

• Each tuple is distinct (i.e., unique)Each tuple is distinct (i.e., unique)

– No duplicate tuplesNo duplicate tuples

• Order of tuples has no significanceOrder of tuples has no significance

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Unique Identification of a RelationUnique Identification of a Relation

RelationRelation

keykey

SuperkeySuperkey

Candidate keyCandidate key

Primary keyPrimary key

Foreign keyForeign key??

8


Identifying a TupleIdentifying a Tuple

• SuperkeySuperkeyAn attribute or a set of attributes that uniquely identifies a tuple An attribute or a set of attributes that uniquely identifies a tuple within a relationwithin a relation

• Candidate keyCandidate keyA super key such that no proper subset is a superkey within the A super key such that no proper subset is a superkey within the relationrelation– Uniquely identifies the tuple (uniqueness)Uniquely identifies the tuple (uniqueness)– Contains no unique subset (irreducibility)Contains no unique subset (irreducibility)

• Primary keyPrimary keyThe candidate key that is selected to identify tuples uniquely The candidate key that is selected to identify tuples uniquely within a relationwithin a relation– Should remain constant over the life of the tupleShould remain constant over the life of the tuple– Most Most efficient efficient way of identifying a tupleway of identifying a tuple

9


Finding the Primary KeyFinding the Primary Key

Super KeySuper Key

Candidate KeyCandidate Key

Primary keyPrimary key

10


KeysKeys

AttributesAttributes• Catalog numberCatalog number• Record titleRecord title• Artist nameArtist name• Record labelRecord label• UPCUPC

CDs RelationCDs Relation

129341129341

129342129342

129343129343

129344129344

Help!Help!

Hard Day’s NightHard Day’s Night

Sergeant Pepper’sSergeant Pepper’s

Magical Mystery TourMagical Mystery Tour

BeatlesBeatles

BeatlesBeatles

BeatlesBeatles

BeatlesBeatles

ColumbiaColumbia

ColumbiaColumbia

ColumbiaColumbia

ColumbiaColumbia

129345129345 Abbey RoadAbbey Road BeatlesBeatles AppleApple

1-29150-8384-01-29150-8384-0

1-29150-7115-01-29150-7115-0

1-29150-2484-01-29150-2484-0

1-29150-7515-01-29150-7515-0

1-15700-9510-01-15700-9510-0

Superkey?Superkey?Candidate key?Candidate key?Primary key?Primary key?

11


Selecting a KeySelecting a Key

• CriteriaCriteria

– An An efficientefficient way of identifying an entity way of identifying an entity

– The attribute (value) remains constant over the life of The attribute (value) remains constant over the life of the entitythe entity

• Never changesNever changes

12


Identifying a TupleIdentifying a Tuple

• Foreign keyForeign keyAn attribute or set of attributes within one relation that An attribute or set of attributes within one relation that matches the candidate key of some (possibly the same) matches the candidate key of some (possibly the same) relationrelation

RelationRelation

keykey

keykey

RelationRelation

foreign keyforeign key

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Foreign KeyForeign Key

CDs RelationCDs Relation

129341129341

129342129342

129343129343

129344129344

Help!Help!

Hard Day’s NightHard Day’s Night

Sergeant Pepper’sSergeant Pepper’s

Magical Mystery TourMagical Mystery Tour

BeatlesBeatles

BeatlesBeatles

BeatlesBeatles

BeatlesBeatles

COLCOL

COLCOL

COLCOL

COLCOL

129345129345 Abbey RoadAbbey Road BeatlesBeatles APPAPP

1-29150-8384-01-29150-8384-0

1-29150-7115-01-29150-7115-0

1-29150-2484-01-29150-2484-0

1-29150-7515-01-29150-7515-0

1-15700-9510-01-15700-9510-0

COLCOL

APPAPP

Columbia RecordsColumbia Records

Apple RecordsApple RecordsRecording Label Recording Label

RelationRelation(home relation)(home relation)

Must match!Must match!

14


Relational IntegrityRelational Integrity

Constraints placed on the set of values allowed for the Constraints placed on the set of values allowed for the attributes of a relation.attributes of a relation.• Entity integrityEntity integrity

– No attribute of a primary key can be null (every tuple No attribute of a primary key can be null (every tuple must be uniquely identified)must be uniquely identified)

• Referential integrityReferential integrity– If a foreign key exists in a relation, either the foreign If a foreign key exists in a relation, either the foreign

key value must match a candidate key value of some key value must match a candidate key value of some tuple in its home relation, or the foreign key value must tuple in its home relation, or the foreign key value must be wholly null (i.e., no key exists in the home relation)be wholly null (i.e., no key exists in the home relation)

• General constraints (reflect business practices)General constraints (reflect business practices)

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Null ValueNull Value

• Absence of any value (i.e., unknown or nonapplicable to a Absence of any value (i.e., unknown or nonapplicable to a tuple)tuple)

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ViewsViews

• A view is a A view is a virtual relation virtual relation or one that does not actually or one that does not actually exist, but exist, but dynamically deriveddynamically derived– Can be constructed by performing operations (i.e., select, Can be constructed by performing operations (i.e., select,

project, join, etc.) on values of existing base relations project, join, etc.) on values of existing base relations • Base relation - a named relation, corresponding to an Base relation - a named relation, corresponding to an

entity in the conceptual schema, whose tuples are entity in the conceptual schema, whose tuples are physically stored in the databasephysically stored in the database

• View - a dynamic result of one or more relational View - a dynamic result of one or more relational operations operating on the base relations to produce operations operating on the base relations to produce anotheranother

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Schema and SubschemasSchema and Subschemas

DBMS

Schema Conceptual LevelConceptual Level

External External LevelLevel

Internal LevelInternal LevelPhysical DatabasePhysical Database

DBMS SoftwareDBMS Software

User User User User User User

Subschema

SomeSome end-user applications end-user applications can be supported by can be supported by viewsviews

Subschema Subschema

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ViewsViews

KeyKeyForeign Foreign

KeyKey KeyKey

CriterionCriterion

Base Relation RBase Relation R Base Relation SBase Relation S

ViewView

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Purpose of ViewsPurpose of Views

• Provides a powerful and flexible security mechanism by Provides a powerful and flexible security mechanism by hiding parts of the database from certain usershiding parts of the database from certain users

• Permits user access in a way that is customized to their Permits user access in a way that is customized to their needsneeds

• Simplify complex operations on the base relationsSimplify complex operations on the base relations

• Designed to support the external model Designed to support the external model

• Provides logical independenceProvides logical independence

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Updating ViewsUpdating Views

• Allowed on views Allowed on views

– Derived from a single base relation, andDerived from a single base relation, and

– Containing the primary key or a candidate keyContaining the primary key or a candidate key

• NOT allowed on viewsNOT allowed on views

– Derived from multiple base relationsDerived from multiple base relations

– Involving aggregations (i.e., summations) or groups Involving aggregations (i.e., summations) or groups operationsoperations

• Vendors may have other constraints on updating viewsVendors may have other constraints on updating views

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Relational LanguagesRelational LanguagesRelational Calculus vs. Relational AlgebraRelational Calculus vs. Relational Algebra

• Relational calculusRelational calculusNonprocedural formal relational data manipulation Nonprocedural formal relational data manipulation language in which the user specifies what data should be language in which the user specifies what data should be retrieved, but retrieved, but notnot how to retrieve it. how to retrieve it.

• Relational algebraRelational algebraA theoretical language with operators that work on one or A theoretical language with operators that work on one or two relations to produce another relation.two relations to produce another relation.

Ricardo, 1990Ricardo, 1990

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Relational AlgebraRelational Algebra

• Fundamental operations:Fundamental operations:

– Selection (Selection ())

– Projection (Projection ())

– Union (Union ())

– Set differenceSet difference

– Intersection (Intersection ())

– Cartesian productCartesian product

– Join ( )Join ( )

– DivisionDivision

Unary operations (applied to a Unary operations (applied to a single relation)single relation)

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Aggregating and Grouping OperationsAggregating and Grouping Operations

• CountCount

• SumSum

• Average (value)Average (value)

• Minimum (value)Minimum (value)

• Maximum (value)Maximum (value)

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SelectionSelection

• Selection operator works on a Selection operator works on a singlesingle relation and defines a relation and defines a relation that contains only those tuples that satisfy the relation that contains only those tuples that satisfy the specified condition (specified condition (predicatepredicate))

predicatepredicate(R) (R) predicatepredicate(R) (R)

PredicatePredicate

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ProjectionProjection

• Defines a relation that contains a vertical subset, extracting Defines a relation that contains a vertical subset, extracting the values of specified attributes and eliminating the values of specified attributes and eliminating duplicates.duplicates.

attribute-1, ..., attribute-attribute-1, ..., attribute-nn(R)(R)attribute-1, ..., attribute-attribute-1, ..., attribute-nn(R)(R)

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• The selection extracts a subset of tuples from the original The selection extracts a subset of tuples from the original relation R based on the predicate. The project further relation R based on the predicate. The project further reduces the number of attributes. reduces the number of attributes.

Projection on a SelectionProjection on a Selection

attribute-1, ..., attribute-attribute-1, ..., attribute-nn((predicatepredicate(R))(R))attribute-1, ..., attribute-attribute-1, ..., attribute-nn((predicatepredicate(R))(R))

Original relationOriginal relation

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Project on a SelectionProject on a Selection

3ABC1233ABC123 Acura TLAcura TL SilverSilver4MIS3454MIS345 Honda Accord DX Honda Accord DX WhiteWhite4MIS8374MIS837 Honda Accord LXHonda Accord LX BlackBlack4LLP3944LLP394 Lexus GS400Lexus GS400 SilverSilver4NOP9344NOP934 Acura CLAcura CL MetBlueMetBlue4TLC3944TLC394 Mercedes CLK320Mercedes CLK320 RedRed4MSE2914MSE291 BMW 525i BMW 525i TealTeal5AMD0425AMD042 BMW M RoadsterBMW M Roadster BlueMetBlueMet4GAS2944GAS294 Lexus LS430Lexus LS430 GoldMetGoldMet


Carslicense, makelicense, make((color=‘Silver’color=‘Silver’(Cars))(Cars))license, makelicense, make((color=‘Silver’color=‘Silver’(Cars))(Cars))

3ABC1233ABC123 Acura TLAcura TL SilverSilver4LLP3944LLP394 Lexus GS400Lexus GS400 SilverSilver3ABC1233ABC123 Acura TLAcura TL SilverSilver4LLP3944LLP394 Lexus GS400Lexus GS400 SilverSilver

Step 1Step 1Step 1Step 1

color=‘Silver’color=‘Silver’

3ABC1233ABC123 Acura TLAcura TL4LLP3944LLP394 Lexus GS400Lexus GS4003ABC1233ABC123 Acura TLAcura TL4LLP3944LLP394 Lexus GS400Lexus GS400

Step 2Step 2Step 2Step 2license, license,

makemake

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UnionUnion

• The union of two relations The union of two relations RR and and SS with with II and and JJ tuples, tuples, receptively, is obtained by concatenating them into one receptively, is obtained by concatenating them into one relation with a maximum of (relation with a maximum of (II + + JJ) tuples, duplicate tuples ) tuples, duplicate tuples being eliminated.being eliminated.

– RR and and SS must be union compatible (i.e., same attributes) must be union compatible (i.e., same attributes)

R R S S R R S S RR SS

attribute-1, ..., attribute-attribute-1, ..., attribute-nn((RR) ) attribute-1, ..., attribute-attribute-1, ..., attribute-nn((SS) ) attribute-1, ..., attribute-attribute-1, ..., attribute-nn((RR) ) attribute-1, ..., attribute-attribute-1, ..., attribute-nn((SS) )

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UnionUnion

3ABC1233ABC123 Acura TLAcura TL SilverSilver4MIS3454MIS345 Honda Accord DX Honda Accord DX WhiteWhite4MIS8374MIS837 Honda Accord LXHonda Accord LX BlackBlack4LLP3944LLP394 Lexus GS400Lexus GS400 SilverSilver4NOP9344NOP934 Acura CLAcura CL MetBlueMetBlue


4TLC3944TLC394 Mercedes CLK320Mercedes CLK320 RedRed4MSE2914MSE291 BMW 525i BMW 525i TealTeal5AMD0425AMD042 BMW M RoadsterBMW M Roadster BlueMetBlueMet4LLP3944LLP394 Lexus GS400Lexus GS400 SilverSilver4GAS2944GAS294 Lexus LS430Lexus LS430 GoldMetGoldMet


Set 1

Set 2



Common

R R S S R R S S

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Set DifferenceSet Difference

• Defines a relation consisting of the tuples that are in Defines a relation consisting of the tuples that are in relation relation RR, but not in , but not in SS..

– RR and and SS must be union-compatible (i.e., same attributes) must be union-compatible (i.e., same attributes)



31







Set 1

Set 2

license, model, colorlicense, model, color(Set 1) (Set 1) license, model, colorlicense, model, color(Set 2) (Set 2) license, model, colorlicense, model, color(Set 1) (Set 1) license, model, colorlicense, model, color(Set 2) (Set 2)

3ABC1233ABC123 Acura TLAcura TL SilverSilver4MIS3454MIS345 Honda Accord DX Honda Accord DX WhiteWhite4MIS8374MIS837 Honda Accord LXHonda Accord LX BlackBlack4NOP9344NOP934 Acura CLAcura CL MetBlueMetBlue

3ABC1233ABC123 Acura TLAcura TL SilverSilver4MIS3454MIS345 Honda Accord DX Honda Accord DX WhiteWhite4MIS8374MIS837 Honda Accord LXHonda Accord LX BlackBlack4NOP9344NOP934 Acura CLAcura CL MetBlueMetBlue

Not unique to Set 1

R R S S R R S S Set 1Set 1 Set 2Set 2

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attribute-1, ..., attribute-attribute-1, ..., attribute-nn((SS) ) attribute-1, ..., attribute-attribute-1, ..., attribute-nn((RR) ) attribute-1, ..., attribute-attribute-1, ..., attribute-nn((SS) ) attribute-1, ..., attribute-attribute-1, ..., attribute-nn((RR) )

ReversedReversed

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Set 1

Set 2

license, model, colorlicense, model, color(Set 2) (Set 2) license, model, colorlicense, model, color(Set 1) (Set 1) license, model, colorlicense, model, color(Set 2) (Set 2) license, model, colorlicense, model, color(Set 1) (Set 1)

4TLC3944TLC394 Mercedes CLK320Mercedes CLK320 RedRed4MSE2914MSE291 BMW 525i BMW 525i TealTeal5AMD0425AMD042 BMW M RoadsterBMW M Roadster BlueMetBlueMet4GAS2944GAS294 Lexus LS430Lexus LS430 GoldMetGoldMet

4TLC3944TLC394 Mercedes CLK320Mercedes CLK320 RedRed4MSE2914MSE291 BMW 525i BMW 525i TealTeal5AMD0425AMD042 BMW M RoadsterBMW M Roadster BlueMetBlueMet4GAS2944GAS294 Lexus LS430Lexus LS430 GoldMetGoldMet


34


IntersectionIntersection

• An intersection consists of the set of all tuples that are in An intersection consists of the set of all tuples that are in both both RR and and SS..

– RR and and SS must be union-compatible (i.e., same attributes) must be union-compatible (i.e., same attributes)



35


IntersectionIntersection





4LLP3944LLP394 Lexus GS400Lexus GS400 SilverSilver4LLP3944LLP394 Lexus GS400Lexus GS400 SilverSilver

Set 1

Set 2


36


Cartesian ProductCartesian Product

• The Cartesian product defines a relation that is the The Cartesian product defines a relation that is the concatenation of every tuple of relation concatenation of every tuple of relation RR with every tuple with every tuple of relation of relation SS

– II JJ tuples tuples

– N N ++ M M attributes attributes


37


Cartesian ProductCartesian Product

a, b, u, va, b, u, va, b, w, xa, b, w, xa, b, y, za, b, y, zc, d, u ,vc, d, u ,vc, d, w, xc, d, w, xc, d, y, zc, d, y, ze, f, u, ve, f, u, ve, f, w, xe, f, w, xe, f, y, ze, f, y, z

Cartesian Cartesian ProductProduct

a, ba, bc, dc, de, fe, f

Relation Relation RR

u, vu, vw, xw, xy, zy, z

Relation Relation SS

}}

}}}}

RR SS

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JoinsJoins

• Theta joinTheta join

• Equi-joinEqui-join

• Natural joinNatural join

• Outer joinOuter join

• Semi-joinSemi-join

Selection performed on two Selection performed on two relations, relations, RR and and SS, that share at , that share at least a single common attributeleast a single common attribute

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Theta-Join vs. Equi-JoinTheta-Join vs. Equi-Join

• Theta-joinTheta-joinA resulting relation that contains tuples satisfying the A resulting relation that contains tuples satisfying the predicate predicate FF from the Cartesian product of from the Cartesian product of RR and and SS– The predicate The predicate FF is of the form is of the form

where where may be one of the comparison operators <, <=, may be one of the comparison operators <, <=, >, >=, <>>, >=, <>

• Equi-joinEqui-join– Where Where is ‘=‘ is ‘=‘

RR.a.ajj SS.b.bj j RR.a.ajj SS.b.bj j

RR FFSSRR FFSS

RR RR.aj .aj SS.bj .bj SSRR RR.aj .aj SS.bj .bj SS

40


Theta JoinTheta Join

CarsLS340LS340 LexusLexusGS300GS300 LexusLexusGS430GS430 LexusLexusC320C320 MBMBE320E320 MBMBS430S430 MBMB325i325i BMWBMW523i523i BMWBMW530i530i BMWBMW

LS340LS340 LexusLexusGS300GS300 LexusLexusGS430GS430 LexusLexusC320C320 MBMBE320E320 MBMBS430S430 MBMB325i325i BMWBMW523i523i BMWBMW530i530i BMWBMW

LexusLexus www.lexus.comwww.lexus.comMBMB www.mercedesbenz.comwww.mercedesbenz.comBMWBMW www.bmw.comwww.bmw.com


Manufacturers(( model model ((CarsCars)) )) cars.make < ‘MB’cars.make < ‘MB’ (( URLURL((ManufacturersManufacturers))))(( model model ((CarsCars)) )) cars.make < ‘MB’cars.make < ‘MB’ (( URLURL((ManufacturersManufacturers))))

LS340LS340 www.lexus.comwww.lexus.comGS300GS300 www.lexus.comwww.lexus.comGS430GS430 www.lexus.comwww.lexus.com325i325i www.bmw.comwww.bmw.com523i523i www.bmw.comwww.bmw.com530i530i www.bmw.comwww.bmw.com

LS340LS340 www.lexus.comwww.lexus.comGS300GS300 www.lexus.comwww.lexus.comGS430GS430 www.lexus.comwww.lexus.com325i325i www.bmw.comwww.bmw.com523i523i www.bmw.comwww.bmw.com530i530i www.bmw.comwww.bmw.com

modelmodel URLURL

model

URL

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Equi-JoinEqui-Join

CarsLS340LS340 LexusLexusGS300GS300 LexusLexusGS430GS430 LexusLexusC320C320 MBMBE320E320 MBMBS430S430 MBMB325i325i BMWBMW523i523i BMWBMW530i530i BMWBMWS8S8 AudiAudi

LS340LS340 LexusLexusGS300GS300 LexusLexusGS430GS430 LexusLexusC320C320 MBMBE320E320 MBMBS430S430 MBMB325i325i BMWBMW523i523i BMWBMW530i530i BMWBMWS8S8 AudiAudi

LexusLexus www.lexus.comwww.lexus.comMBMB www.mercedesbenz.comwww.mercedesbenz.comBMWBMW www.bmw.comwww.bmw.comPorschePorsche www.porsche.comwww.porsche.com


Manufacturers(( model model((CarsCars)) )) cars.make=manufacturers .makecars.make=manufacturers .make(( URLURL((ManufacturersManufacturers))))(( model model((CarsCars)) )) cars.make=manufacturers .makecars.make=manufacturers .make(( URLURL((ManufacturersManufacturers))))

modelmodel URLURLLS340LS340 www.lexus.comwww.lexus.comGS300GS300 www.lexus.comwww.lexus.comGS430GS430 www.lexus.comwww.lexus.comC320C320 www.mercedesbenz.comwww.mercedesbenz.comE320E320 www.mercedesbenz.comwww.mercedesbenz.comS430S430 www.mercedesbenz.comwww.mercedesbenz.com325i325i www.bmw.comwww.bmw.com523i523i www.bmw.comwww.bmw.com530i530i www.bmw.comwww.bmw.com

LS340LS340 www.lexus.comwww.lexus.comGS300GS300 www.lexus.comwww.lexus.comGS430GS430 www.lexus.comwww.lexus.comC320C320 www.mercedesbenz.comwww.mercedesbenz.comE320E320 www.mercedesbenz.comwww.mercedesbenz.comS430S430 www.mercedesbenz.comwww.mercedesbenz.com325i325i www.bmw.comwww.bmw.com523i523i www.bmw.comwww.bmw.com530i530i www.bmw.comwww.bmw.com

model

URL

No match

No match

42


Natural JoinNatural Join

• Equi-join of two relations Equi-join of two relations RR and and SS over all common over all common attributes attributes xx

– One occurrence of each common attribute is eliminated One occurrence of each common attribute is eliminated from the resultfrom the result

R R SSR R SS

43


Natural JoinNatural Join

CarsLS340LS340 LexusLexusGS300GS300 LexusLexusGS430GS430 LexusLexusC320C320 MBMBE320E320 MBMBS430S430 MBMB325i325i BMWBMW523i523i BMWBMW530i530i BMWBMW

LS340LS340 LexusLexusGS300GS300 LexusLexusGS430GS430 LexusLexusC320C320 MBMBE320E320 MBMBS430S430 MBMB325i325i BMWBMW523i523i BMWBMW530i530i BMWBMW



Manufacturers

(( model, make model, make ((CarsCars)) )) cars.make=manufacturers .makecars.make=manufacturers .make

(( make, URLmake, URL((ManufacturersManufacturers))))

(( model, make model, make ((CarsCars)) )) cars.make=manufacturers .makecars.make=manufacturers .make

(( make, URLmake, URL((ManufacturersManufacturers))))

““Make” not repeatedMake” not repeated

LS340LS340 LexusLexus www.lexus.comwww.lexus.comGS300GS300 LexusLexus www.lexus.comwww.lexus.comGS430GS430 LexusLexus www.lexus.comwww.lexus.comC320C320 MBMB www.mercedesbenz.comwww.mercedesbenz.comE320E320 MBMB www.mercedesbenz.comwww.mercedesbenz.comS430S430 MBMB www.mercedesbenz.comwww.mercedesbenz.com325i325i BMWBMW www.bmw.comwww.bmw.com523i523i BMWBMW www.bmw.comwww.bmw.com530i530i BMWBMW www.bmw.comwww.bmw.com

LS340LS340 LexusLexus www.lexus.comwww.lexus.comGS300GS300 LexusLexus www.lexus.comwww.lexus.comGS430GS430 LexusLexus www.lexus.comwww.lexus.comC320C320 MBMB www.mercedesbenz.comwww.mercedesbenz.comE320E320 MBMB www.mercedesbenz.comwww.mercedesbenz.comS430S430 MBMB www.mercedesbenz.comwww.mercedesbenz.com325i325i BMWBMW www.bmw.comwww.bmw.com523i523i BMWBMW www.bmw.comwww.bmw.com530i530i BMWBMW www.bmw.comwww.bmw.com

44


Outer JoinOuter Join

• A join in which tuples from A join in which tuples from RR that do not have matching that do not have matching values in the common attributes of values in the common attributes of SS are also included in are also included in the result relation.the result relation.

– Missing values in the second relation are set to nullMissing values in the second relation are set to null

– Right outer join (all tuples on right kept) Right outer join (all tuples on right kept) vs. left outer join (all tuples on the left kept) vs. left outer join (all tuples on the left kept) vs. full outer join (all tuples on both sides kept)vs. full outer join (all tuples on both sides kept)

RR SSRR SS

45


Left Outer JoinLeft Outer Join





Manufacturers model model ((CarsCars) ) cars.make=manufacturers.makecars.make=manufacturers.make URL URL((ManufacturersManufacturers)) model model ((CarsCars) ) cars.make=manufacturers.makecars.make=manufacturers.make URL URL((ManufacturersManufacturers))

LS340LS340 www.lexus.comwww.lexus.comGS300GS300 www.lexus.comwww.lexus.comGS430GS430 www.lexus.comwww.lexus.comC320C320 www.mercedesbenz.comwww.mercedesbenz.comE320E320 www.mercedesbenz.comwww.mercedesbenz.comS430S430 www.mercedesbenz.comwww.mercedesbenz.com325i325i www.bmw.comwww.bmw.com523i523i www.bmw.comwww.bmw.com530i530i www.bmw.comwww.bmw.comS8S8 nullnull

LS340LS340 www.lexus.comwww.lexus.comGS300GS300 www.lexus.comwww.lexus.comGS430GS430 www.lexus.comwww.lexus.comC320C320 www.mercedesbenz.comwww.mercedesbenz.comE320E320 www.mercedesbenz.comwww.mercedesbenz.comS430S430 www.mercedesbenz.comwww.mercedesbenz.com325i325i www.bmw.comwww.bmw.com523i523i www.bmw.comwww.bmw.com530i530i www.bmw.comwww.bmw.comS8S8 nullnull

Match all the models in Cars to the URLs in Manufacturers

No match found

46


Right Outer JoinRight Outer Join





Manufacturers model model ((CarsCars) ) cars.make=manufacturers.makecars.make=manufacturers.make URL URL((ManufacturersManufacturers)) model model ((CarsCars) ) cars.make=manufacturers.makecars.make=manufacturers.make URL URL((ManufacturersManufacturers))

LS340LS340 www.lexus.comwww.lexus.comGS300GS300 www.lexus.comwww.lexus.comGS430GS430 www.lexus.comwww.lexus.comC320C320 www.mercedesbenz.comwww.mercedesbenz.comE320E320 www.mercedesbenz.comwww.mercedesbenz.comS430S430 www.mercedesbenz.comwww.mercedesbenz.com325i325i www.bmw.comwww.bmw.com523i523i www.bmw.comwww.bmw.com530i530i www.bmw.comwww.bmw.comnullnull www.porsche.comwww.porsche.com

LS340LS340 www.lexus.comwww.lexus.comGS300GS300 www.lexus.comwww.lexus.comGS430GS430 www.lexus.comwww.lexus.comC320C320 www.mercedesbenz.comwww.mercedesbenz.comE320E320 www.mercedesbenz.comwww.mercedesbenz.comS430S430 www.mercedesbenz.comwww.mercedesbenz.com325i325i www.bmw.comwww.bmw.com523i523i www.bmw.comwww.bmw.com530i530i www.bmw.comwww.bmw.comnullnull www.porsche.comwww.porsche.com

Match all the URLs in Manufacturers to the models in Cars

No match found

47


DivisionDivision

• Consists of the set of tuples from Consists of the set of tuples from RR defined over the defined over the attributes attributes CC that match the combination of every tuple in that match the combination of every tuple in SS

attribute-xattribute-x((RR) ) attribute-xattribute-x(( predicatepredicate((SS)) )) attribute-xattribute-x((RR) ) attribute-xattribute-x(( predicatepredicate((SS)) ))

SelectSelect

Project of Select Project of Select T2T2Project R Project R T1T1

Occurrences in project T1 that match the pattern in T2Occurrences in project T1 that match the pattern in T2

48


rno,pnorno,pno((ViewingViewing) ) pnopno((rooms=3rooms=3((Property_for_RentProperty_for_Rent))))(Identify all renters who have viewed all properties with 3 rooms)(Identify all renters who have viewed all properties with 3 rooms)

rno,pnorno,pno((ViewingViewing) ) pnopno((rooms=3rooms=3((Property_for_RentProperty_for_Rent))))(Identify all renters who have viewed all properties with 3 rooms)(Identify all renters who have viewed all properties with 3 rooms)

RnoRno PnoPno DateDate CommentCommentCR56 CR56 PA14 5/24/95 PA14 5/24/95 Too smallToo smallCR76CR76 PG4PG4 4/20/954/20/95 Too remoteToo remoteCR56CR56 PG4PG4 5/26/955/26/95CR62CR62 PA14PA14 5/14/955/14/95 No dining roomNo dining roomCR56CR56 PG36PG36 4/28/954/28/95


ViewingViewing

Property_for_RentProperty_for_Rent

PnoPno StreetStreet AreaArea CityCity PcodePcode TypeType RoomsRooms RentRent OnoOno Sno Sno BnoBnoPA14PA14 6 6PL94PL94 4 4PG4PG4 33PG36PG36 33PG21PG21 5 5PG16PG16 4 4

PnoPno StreetStreet AreaArea CityCity PcodePcode TypeType RoomsRooms RentRent OnoOno Sno Sno BnoBnoPA14PA14 6 6PL94PL94 4 4PG4PG4 33PG36PG36 33PG21PG21 5 5PG16PG16 4 4

Rno = Renter NumberRno = Renter Number

49


rno,pnorno,pno((ViewingViewing) ) pnopno(( rooms=3rooms=3((Property_for_RentProperty_for_Rent))))(Select Property_for_Rent with rooms = 3)(Select Property_for_Rent with rooms = 3)

rno,pnorno,pno((ViewingViewing) ) pnopno(( rooms=3rooms=3((Property_for_RentProperty_for_Rent))))(Select Property_for_Rent with rooms = 3)(Select Property_for_Rent with rooms = 3)

PnoPno StreetStreet AreaArea CityCity PcodePcode TypeType RoomsRooms RentRent OnoOno Sno Sno BnoBnoPG4PG4 3 3PG36PG36 3 3


Property_for_RentProperty_for_Rent

PnoPno StreetStreet AreaArea CityCity PcodePcode TypeType RoomsRooms RentRent OnoOno Sno Sno BnoBnoPA14PA14 6 6PL94PL94 4 4PG4PG4 3 3PG36PG36 3 3PG21PG21 5 5PG16PG16 4 4

PnoPno StreetStreet AreaArea CityCity PcodePcode TypeType RoomsRooms RentRent OnoOno Sno Sno BnoBnoPA14PA14 6 6PL94PL94 4 4PG4PG4 3 3PG36PG36 3 3PG21PG21 5 5PG16PG16 4 4

(( rooms=3rooms=3((Property_for_RentProperty_for_Rent))

50


pnopno(( rooms=3rooms=3((Property_for_RentProperty_for_Rent))

rno,pnorno,pno((ViewingViewing) ) pnopno(( rooms=3rooms=3((Property_for_RentProperty_for_Rent))))(Project proper number)(Project proper number)

rno,pnorno,pno((ViewingViewing) ) pnopno(( rooms=3rooms=3((Property_for_RentProperty_for_Rent))))(Project proper number)(Project proper number)



Select(Property_for_Rent)Select(Property_for_Rent)

PnoPnoPG4PG4PG36PG36

PnoPnoPG4PG4PG36PG36 All properties for All properties for

rent with 3 rooms.rent with 3 rooms.

51


RnoRno PnoPnoCR56 CR56 PA14PA14CR76CR76 PG4PG4CR56CR56 PG4PG4CR62CR62 PA14PA14CR56CR56 PG36PG36


rno,pnorno,pno((ViewingViewing) ) pnopno(( rooms=3rooms=3((Property_for_RentProperty_for_Rent))))(Project renter number and property number)(Project renter number and property number)

rno,pnorno,pno((ViewingViewing) ) pnopno(( rooms=3rooms=3((Property_for_RentProperty_for_Rent))))(Project renter number and property number)(Project renter number and property number)



ViewingViewing

rno,pnorno,pno

52


rno,pnorno,pno((ViewingViewing) ) pnopno(( rooms=3rooms=3((Property_for_RentProperty_for_Rent))))rno,pnorno,pno((ViewingViewing) ) pnopno(( rooms=3rooms=3((Property_for_RentProperty_for_Rent))))





Who has viewed Who has viewed allall rental properties with rental properties with 3 rooms?3 rooms?

Renters who have Renters who have viewed propertiesviewed properties

All rental All rental properties with properties with 3 rooms3 rooms

53


rno,pnorno,pno((ViewingViewing) ) pnopno(( rooms=3rooms=3((Property_for_RentProperty_for_Rent))))rno,pnorno,pno((ViewingViewing) ) pnopno(( rooms=3rooms=3((Property_for_RentProperty_for_Rent))))





Who has viewed Who has viewed allall rental properties with rental properties with 3 rooms?3 rooms?

Renter CR76 has viewed PG4, but not PG36Renter CR76 has viewed PG4, but not PG36



54


RnoRnoCR56CR56

RnoRnoCR56CR56

rno,pnorno,pno((ViewingViewing) ) pnopno(( rooms=3rooms=3((Property_for_RentProperty_for_Rent))))(Identify all renters who have viewed all properties with three (Identify all renters who have viewed all properties with three

rooms)rooms)

rno,pnorno,pno((ViewingViewing) ) pnopno(( rooms=3rooms=3((Property_for_RentProperty_for_Rent))))(Identify all renters who have viewed all properties with three (Identify all renters who have viewed all properties with three

rooms)rooms)




PnoPnoPG4PG4PG36PG36{{


Renter number CR56 has Renter number CR56 has viewed viewed allall properties properties with 3 roomswith 3 rooms


Who has viewed all Who has viewed all rental properties with rental properties with 3 rooms?3 rooms?

55


Relational CalculusRelational Calculus

• Specifies Specifies whatwhat is to be retrieved rather than is to be retrieved rather than howhow to retrieve to retrieve itit

– Predicate (truth-value function arguments)Predicate (truth-value function arguments)

– Proposition (arguments replaced with values including Proposition (arguments replaced with values including the predicate)the predicate)

For all For all xx, if , if PP is true (e.g., for all is true (e.g., for all xx if predicate ( if predicate (xx > 100) > 100) is true)is true)

{{xx | P( | P(xx)} )} {{xx | P( | P(xx)} )} Where Where PP is the predicate is the predicate

56


Tuple Oriented vs. Domain Oriented Tuple Oriented vs. Domain Oriented Relational CalculusRelational Calculus

• Tuple oriented (entities or rows)Tuple oriented (entities or rows)Finding tuples for which a predicate is trueFinding tuples for which a predicate is true

– Tuple variables (ranges over a named relation)Tuple variables (ranges over a named relation)

– Quantifiers: Quantifiers:

• Existential (Existential (): there exists (one instance)): there exists (one instance)

• Universal (Universal (): for all): for all

• Domain oriented (attributes or columns)Domain oriented (attributes or columns)Test for membership conditionTest for membership condition

– Variables that take their values from domainsVariables that take their values from domains

Number of Number of tuples to be tuples to be applied toapplied to

57


SQL (pronounced ‘sequel’)SQL (pronounced ‘sequel’)

• ProjectionProjection

• SelectionSelection

58


Structured Query Language (SQL)Structured Query Language (SQL)

• Transform-oriented language:Transform-oriented language:– DDL (data definition language)DDL (data definition language)– DML (data manipulation language)DML (data manipulation language)

• Non-procedural (no logic structure required)Non-procedural (no logic structure required)– Specify Specify whatwhat information is required, rather than information is required, rather than howhow

that information should be retrievedthat information should be retrieved– Format-free (not bound to columns)Format-free (not bound to columns)– English-like (English-like (although abbreviatedalthough abbreviated))

• First standard database language to gain wide acceptanceFirst standard database language to gain wide acceptance– ISO 1992 standards (today ISO 2003)ISO 1992 standards (today ISO 2003)

59


SQL TerminologySQL Terminology

• ISO terminologyISO terminology

– Relations (entity type)Relations (entity type) TablesTables

– Attributes (properties)Attributes (properties) ColumnsColumns

– Tuples (entities)Tuples (entities) RowsRows

columncolumn

Row Row {{

60


SELECT: Basic SyntaxSELECT: Basic Syntax

SELECT SELECT

[DISTINCT | ALL | {* | [column-list [AS alias]] [, ...]}[DISTINCT | ALL | {* | [column-list [AS alias]] [, ...]}

FROM table-name [alias] [, ...]FROM table-name [alias] [, ...]

[WHERE condition][WHERE condition]

[GROUP BY column-list] [HAVING condition][GROUP BY column-list] [HAVING condition]

[ORDER BY column-list][ORDER BY column-list]

[ ] = optional[ ] = optional| = select one option| = select one option

61


Examples Using Products TableExamples Using Products Table

ProductsProducts ( (product_codeproduct_code ( (keykey), product_description, ), product_description, product_cost, product_MSRP, product_retail_price, product_cost, product_MSRP, product_retail_price, retail_unit, manufacturer_code (retail_unit, manufacturer_code (foreign keyforeign key), active_date, ), active_date, number_on_hand, number_on_order, number_committed)number_on_hand, number_on_order, number_committed)

62


ProjectionProjectionPerformed on a Single TablePerformed on a Single Table

product_code, product_descriptionproduct_code, product_description((ProductsProducts))

SELECT product_code, product_descriptionSELECT product_code, product_description

FROM productsFROM products

Result: Result: AllAll rows with only the product_code and rows with only the product_code and product_description columns are retrievedproduct_description columns are retrieved

Column-listColumn-listColumn-listColumn-list

63


SQL> SQL> select product_code, product_description from products;select product_code, product_description from products;

PRODUCT_CO PRODUCT_DESCRIPTION PRODUCT_CO PRODUCT_DESCRIPTION ---------- ------------------------------ ---------- ------------------------------ 301-III Direct/Reflecting Speakers 301-III Direct/Reflecting Speakers 3800 Three-way Speaker System 3800 Three-way Speaker System 4312 Studio Monitors 4312 Studio Monitors 901Classic Direct/Reflecting Spkr System 901Classic Direct/Reflecting Spkr System AM3 Acoustimass Speaker System AM3 Acoustimass Speaker System AM5 Acoustimass 5 Speaker System AM5 Acoustimass 5 Speaker System AM7 Acoustimass 7 Speaker System AM7 Acoustimass 7 Speaker System AT-10 Loudspeakers AT-10 Loudspeakers AT-15 Three-way Speaker AT-15 Three-way Speaker CCS-350 Compact System w/CD Player CCS-350 Compact System w/CD Player CCS-450 Compact System w/CD Player CCS-450 Compact System w/CD Player CCS-550 75-watt System w/CD Changer CCS-550 75-watt System w/CD Changer CD-1000C Compact Disc Changer CD-1000C Compact Disc Changer CDP-297 Compact Disc Player CDP-297 Compact Disc Player CDP-397 Compact Disc Player CDP-397 Compact Disc Player CDP-C225 Disc Jockey CD ChangerCDP-C225 Disc Jockey CD Changer

..

..

..100 rows selected.100 rows selected.

64


SelectionSelectionPerformed on a Single TablePerformed on a Single Table

manufacturer_code = ‘SON’ manufacturer_code = ‘SON’ ((ProductsProducts))

SELECT *SELECT *


WHERE manufacturer_code = ‘SON’WHERE manufacturer_code = ‘SON’

Result: Only those rows with SON for their Result: Only those rows with SON for their manufacturer_code are retrieved along with all columns.manufacturer_code are retrieved along with all columns.

All columnsAll columnsProposition Proposition (predicate)(predicate)

65


Four Ways to Build a SelectionFour Ways to Build a Selection

• Relational operator (=, <, <=, >, >=, <>)Relational operator (=, <, <=, >, >=, <>)– Logical AND and ORLogical AND and OR

WHEREWHERE column-namecolumn-name == xx AND AND column-namecolumn-name = = yy• Specific range using BETWEENSpecific range using BETWEEN

WHEREWHERE column-namecolumn-name BETWEENBETWEEN xx ANDAND yy• Specific values using INSpecific values using IN

WHERE WHERE column-namecolumn-name ININ ( (list-of-valueslist-of-values))• Character match using LIKE and wildcards (%, _)Character match using LIKE and wildcards (%, _)

– UPPER and LOWER functionsUPPER and LOWER functions

WHERE LOWER(WHERE LOWER(column-namecolumn-name) ) LIKELIKE ‘%‘%character-stringcharacter-string%’%’

66


Four ways to build a SELECTION:Four ways to build a SELECTION:

1. Relational and Logical Operators1. Relational and Logical Operators

• Relational operators:Relational operators:

== equalsequals

>, < >, < greater than, less thangreater than, less than

<=<= less than or equal toless than or equal to

>=>= greater than or equal togreater than or equal to

<><> not equal tonot equal to

• Logical operatorsLogical operators

AND, ORAND, OR AND evaluated before ORAND evaluated before OR

NOTNOT NOT evaluated before AND and ORNOT evaluated before AND and OR

67


WHERE (Condition)WHERE (Condition)

SELECT *SELECT *


WHERE manufacturer_code = ‘SON’ WHERE manufacturer_code = ‘SON’

OROR manufacturer_code = ‘PAN’ manufacturer_code = ‘PAN’

SELECT *SELECT *


WHERE product_msrp >= 100 WHERE product_msrp >= 100 ANDAND product_msrp <= 500 product_msrp <= 500

ANDAND product_code = ‘SON’ product_code = ‘SON’ OROR product_code = ‘PAN’ product_code = ‘PAN’

All columnsAll columns

68


select * from products where manufacturer_code='SON';select * from products where manufacturer_code='SON';

PRODUCT_CO PRODUCT_DESCRIPTION PRODUCT_COST PRODUCT_MSRP PRODUCT_RETAIL_PRICE RE MAN PRODUCT_CO PRODUCT_DESCRIPTION PRODUCT_COST PRODUCT_MSRP PRODUCT_RETAIL_PRICE RE MAN ---------- ------------------------------ ------------ ------------ -------------------- -- --- ---------- ------------------------------ ------------ ------------ -------------------- -- --- ACTIVE_DA NUMBER_ON_HAND NUMBER_ON_ORDER NUMBER_COMMITTED ACTIVE_DA NUMBER_ON_HAND NUMBER_ON_ORDER NUMBER_COMMITTED --------- -------------- --------------- ---------------- --------- -------------- --------------- ---------------- CDP-297 Compact Disc Player 84.47 129.95 116.96 EA SON CDP-297 Compact Disc Player 84.47 129.95 116.96 EA SON 25-AUG-96 4 0 0 25-AUG-96 4 0 0 CDP-397 Compact Disc Player 97.47 149.95 134.96 EA SON CDP-397 Compact Disc Player 97.47 149.95 134.96 EA SON 25-AUG-96 11 0 0 25-AUG-96 11 0 0 CDP-C225 Disc Jockey CD Changer 129.97 199.95 179.96 EA SON CDP-C225 Disc Jockey CD Changer 129.97 199.95 179.96 EA SON 25-AUG-96 10 0 0 25-AUG-96 10 0 0 CDP-C325 Disc Jockey CD Changer 149.47 229.95 206.96 EA SON CDP-C325 Disc Jockey CD Changer 149.47 229.95 206.96 EA SON 25-AUG-96 1 0 0 25-AUG-96 1 0 0 CDP-C425 Disc Jockey CD Changer 162.47 249.95 224.96 EA SON CDP-C425 Disc Jockey CD Changer 162.47 249.95 224.96 EA SON 25-AUG-96 5 0 0 25-AUG-96 5 0 0 CDP-C525 Disc Jockey CD Changer 194.97 299.95 269.96 EA SON CDP-C525 Disc Jockey CD Changer 194.97 299.95 269.96 EA SON 25-AUG-96 6 0 0 25-AUG-96 6 0 0 SL-S600 Super-Beta Video Recorder 214.47 329.95 296.96 EA SON SL-S600 Super-Beta Video Recorder 214.47 329.95 296.96 EA SON 25-AUG-96 13 0 0 25-AUG-96 13 0 0 TC-W490 Double Cassette Deck 110.47 169.95 152.96 EA SON TC-W490 Double Cassette Deck 110.47 169.95 152.96 EA SON 25-AUG-96 6 0 0 25-AUG-96 6 0 0

12 rows selected.12 rows selected.

69


Projection on a SelectionProjection on a SelectionPerformed on a Single TablePerformed on a Single Table



WHERE manufacturer_code = ‘SON’ WHERE manufacturer_code = ‘SON’

OR manufacturer_code = ‘PAN’OR manufacturer_code = ‘PAN’

product_code, product_descriptionproduct_code, product_description manufacturer_code = ‘SON’ or ‘PAN’ manufacturer_code = ‘SON’ or ‘PAN’ ((ProductsProducts))))

Column list Predicate (condition)

Only one condition has to be true

70


SQL> SQL> select product_code, product_description from products whereselect product_code, product_description from products where 2 2 manufacturer_code='SON' or manufacturer_code='PAN';manufacturer_code='SON' or manufacturer_code='PAN';

PRODUCT_CO PRODUCT_DESCRIPTION PRODUCT_CO PRODUCT_DESCRIPTION ---------- ------------------------------ ---------- ------------------------------ CDP-297 Compact Disc Player CDP-297 Compact Disc Player CDP-397 Compact Disc Player CDP-397 Compact Disc Player CDP-C225 Disc Jockey CD Changer CDP-C225 Disc Jockey CD Changer CDP-C325 Disc Jockey CD Changer CDP-C325 Disc Jockey CD Changer CDP-C425 Disc Jockey CD Changer CDP-C425 Disc Jockey CD Changer CDP-C525 Disc Jockey CD Changer CDP-C525 Disc Jockey CD Changer PV-2201 HQ VHS Video Cassette Recorde PV-2201 HQ VHS Video Cassette Recorde PV-4210 4-Head VHS Video Cass Recorde PV-4210 4-Head VHS Video Cass Recorde PV-4250 HiFi VHS Video Cass Recorder PV-4250 HiFi VHS Video Cass Recorder SC-T095 Compact Stereo System SC-T095 Compact Stereo System SC-TC430 Compact System w/CD Changer SC-TC430 Compact System w/CD Changer SL-S600 Super-Beta Video Recorder SL-S600 Super-Beta Video Recorder TC-W490 Double Cassette Deck TC-W490 Double Cassette Deck TC-WR590 Double Cassette Deck TC-WR590 Double Cassette Deck TC-WR690 Double Cassette Deck TC-WR690 Double Cassette Deck TC-WR790 Double Cassette Deck TC-WR790 Double Cassette Deck TC-WR875 Double Cassette Deck TC-WR875 Double Cassette Deck


71


SQL> SQL> select product_code, product_description, product_msrpselect product_code, product_description, product_msrp 22 from productsfrom products 3 3 where manufacturer_code='SON' or manufacturer_code='PAN'where manufacturer_code='SON' or manufacturer_code='PAN' 4 4 and product_msrp >= 100 and product_msrp <=500;and product_msrp >= 100 and product_msrp <=500;

PRODUCT_CO PRODUCT_DESCRIPTION PRODUCT_MSRP PRODUCT_CO PRODUCT_DESCRIPTION PRODUCT_MSRP ---------- ------------------------------ ------------ ---------- ------------------------------ ------------ CDP-297 Compact Disc Player 129.95 CDP-297 Compact Disc Player 129.95 CDP-397 Compact Disc Player 149.95 CDP-397 Compact Disc Player 149.95 CDP-C225 Disc Jockey CD Changer 199.95 CDP-C225 Disc Jockey CD Changer 199.95 CDP-C325 Disc Jockey CD Changer 229.95 CDP-C325 Disc Jockey CD Changer 229.95 CDP-C425 Disc Jockey CD Changer 249.95 CDP-C425 Disc Jockey CD Changer 249.95 CDP-C525 Disc Jockey CD Changer 299.95 CDP-C525 Disc Jockey CD Changer 299.95 PV-2201 HQ VHS Video Cassette Recorde 229.95 PV-2201 HQ VHS Video Cassette Recorde 229.95 PV-4210 4-Head VHS Video Cass Recorde 299.95 PV-4210 4-Head VHS Video Cass Recorde 299.95 PV-4250 HiFi VHS Video Cass Recorder 349.95 PV-4250 HiFi VHS Video Cass Recorder 349.95 SC-T095 Compact Stereo System 139.95 SC-T095 Compact Stereo System 139.95 SC-TC430 Compact System w/CD Changer 429.95 SC-TC430 Compact System w/CD Changer 429.95 SL-S600 Super-Beta Video Recorder 329.95 SL-S600 Super-Beta Video Recorder 329.95 TC-W490 Double Cassette Deck 169.95 TC-W490 Double Cassette Deck 169.95 TC-WR590 Double Cassette Deck 199.95 TC-WR590 Double Cassette Deck 199.95 TC-WR690 Double Cassette Deck 249.95 TC-WR690 Double Cassette Deck 249.95 TC-WR790 Double Cassette Deck 329.95 TC-WR790 Double Cassette Deck 329.95 TC-WR875 Double Cassette Deck 429.95 TC-WR875 Double Cassette Deck 429.95


Both conditions Both conditions must be truemust be true

72


Four ways to build a SELECTION:Four ways to build a SELECTION: 2. Range Search with BETWEEN2. Range Search with BETWEEN

SELECT product_code, product_description, product_msrpSELECT product_code, product_description, product_msrp


WHERE product_msrp BETWEEN 100 and 500WHERE product_msrp BETWEEN 100 and 500

AND manufacturer_code = ‘SON’ OR manufacturer_code = AND manufacturer_code = ‘SON’ OR manufacturer_code = ‘PAN’‘PAN’

InclusiveInclusive

73


SQL> SQL> select product_code, product_description, product_msrp,select product_code, product_description, product_msrp, 2 2 manufacturer_codemanufacturer_code 3 3 from productsfrom products 4 4 where manufacturer_code = 'SON' or manufacturer_code = 'PAN' where manufacturer_code = 'SON' or manufacturer_code = 'PAN' 5 5 and product_msrp between 100 and 500;and product_msrp between 100 and 500;

PRODUCT_CO PRODUCT_DESCRIPTION PRODUCT_MSRP MAN PRODUCT_CO PRODUCT_DESCRIPTION PRODUCT_MSRP MAN ---------- ------------------------------ ------------ --- ---------- ------------------------------ ------------ --- CDP-297 Compact Disc Player 129.95 SON CDP-297 Compact Disc Player 129.95 SON CDP-397 Compact Disc Player 149.95 SON CDP-397 Compact Disc Player 149.95 SON CDP-C225 Disc Jockey CD Changer 199.95 SON CDP-C225 Disc Jockey CD Changer 199.95 SON CDP-C325 Disc Jockey CD Changer 229.95 SON CDP-C325 Disc Jockey CD Changer 229.95 SON CDP-C425 Disc Jockey CD Changer 249.95 SON CDP-C425 Disc Jockey CD Changer 249.95 SON CDP-C525 Disc Jockey CD Changer 299.95 SON CDP-C525 Disc Jockey CD Changer 299.95 SON PV-2201 HQ VHS Video Cassette Recorde 229.95 PAN PV-2201 HQ VHS Video Cassette Recorde 229.95 PAN PV-4210 4-Head VHS Video Cass Recorde 299.95 PAN PV-4210 4-Head VHS Video Cass Recorde 299.95 PAN PV-4250 HiFi VHS Video Cass Recorder 349.95 PAN PV-4250 HiFi VHS Video Cass Recorder 349.95 PAN SC-T095 Compact Stereo System 139.95 PAN SC-T095 Compact Stereo System 139.95 PAN SC-TC430 Compact System w/CD Changer 429.95 PAN SC-TC430 Compact System w/CD Changer 429.95 PAN SL-S600 Super-Beta Video Recorder 329.95 SON SL-S600 Super-Beta Video Recorder 329.95 SON TC-W490 Double Cassette Deck 169.95 SON TC-W490 Double Cassette Deck 169.95 SON TC-WR590 Double Cassette Deck 199.95 SON TC-WR590 Double Cassette Deck 199.95 SON TC-WR690 Double Cassette Deck 249.95 SON TC-WR690 Double Cassette Deck 249.95 SON TC-WR790 Double Cassette Deck 329.95 SON TC-WR790 Double Cassette Deck 329.95 SON TC-WR875 Double Cassette Deck 429.95 SON TC-WR875 Double Cassette Deck 429.95 SON


74


Four ways to build a SELECTION:Four ways to build a SELECTION: 3. Search for Specific Values Using IN3. Search for Specific Values Using IN



WHERE manufacturer_code IN ('SON', 'PAN', 'BOS');WHERE manufacturer_code IN ('SON', 'PAN', 'BOS');

List of valuesList of values

75


SQL> SQL> select product_code, product_descriptionselect product_code, product_description 2 2 from productsfrom products 3 3 where manufacturer_code in ('SON', 'PAN', 'BOS');where manufacturer_code in ('SON', 'PAN', 'BOS');

PRODUCT_CO PRODUCT_DESCRIPTIONPRODUCT_CO PRODUCT_DESCRIPTION---------- --------------------------------------------- -----------------------------------DVD-A110 DVD/CD PlayerDVD-A110 DVD/CD PlayerDVP-S7000 DVD/CD PlayerDVP-S7000 DVD/CD PlayerDVP-S3000 DVD/CD PlayerDVP-S3000 DVD/CD PlayerDVP-S500D DVD/CD PlayerDVP-S500D DVD/CD PlayerKV-20S40 20" Trinitron TVKV-20S40 20" Trinitron TVKV-20V80 20" Digital Comb Filter TVKV-20V80 20" Digital Comb Filter TVKV-27V22 27" Trinitron TVKV-27V22 27" Trinitron TVKV-27V26 27" Trinitron TVKV-27V26 27" Trinitron TVKV-27V36 27" Picture-in-Picture TVKV-27V36 27" Picture-in-Picture TVKV-32V36 32" 1-Tuner PIP TVKV-32V36 32" 1-Tuner PIP TVKV-35V36 35" 1-Tuner PIP TVKV-35V36 35" 1-Tuner PIP TVKV-32XBR48 32" Trinitron XBR TVKV-32XBR48 32" Trinitron XBR TVKV-35XBR48 35" Trinitron XBR TVKV-35XBR48 35" Trinitron XBR TVKV-35XBR88 35" Trinitron XBR TVKV-35XBR88 35" Trinitron XBR TV

..

..

..TC-KE500S Cassette DeckTC-KE500S Cassette Deck


76


Four ways to build a SELECTION:Four ways to build a SELECTION: 4. Pattern Match with LIKE4. Pattern Match with LIKE

• Wildcard charactersWildcard characters– % = any sequence of zero or more characters% = any sequence of zero or more characters– _ (underscore) = any single character_ (underscore) = any single character



WHERE product_code LIKE ‘C%’WHERE product_code LIKE ‘C%’

Result:Result: All rows with product codes beginning with C and All rows with product codes beginning with C and their corresponding product_description will be retrieved.their corresponding product_description will be retrieved.

77


SQL> SQL> select product_code, product_description from productsselect product_code, product_description from products 2 2 where product_code like 'C%';where product_code like 'C%';

PRODUCT_CO PRODUCT_DESCRIPTION PRODUCT_CO PRODUCT_DESCRIPTION ---------- ------------------------------ ---------- ------------------------------ CCS-350 Compact System w/CD Player CCS-350 Compact System w/CD Player CCS-450 Compact System w/CD Player CCS-450 Compact System w/CD Player CCS-550 75-watt System w/CD Changer CCS-550 75-watt System w/CD Changer CD-1000C Compact Disc Changer CD-1000C Compact Disc Changer CDP-297 Compact Disc Player CDP-297 Compact Disc Player CDP-397 Compact Disc Player CDP-397 Compact Disc Player CDP-C225 Disc Jockey CD Changer CDP-C225 Disc Jockey CD Changer CDP-C325 Disc Jockey CD Changer CDP-C325 Disc Jockey CD Changer CDP-C425 Disc Jockey CD Changer CDP-C425 Disc Jockey CD Changer CDP-C525 Disc Jockey CD Changer CDP-C525 Disc Jockey CD Changer CS-13RX 13" Color Television CS-13RX 13" Color Television CS-13SX1 13" Stereo Monitor/Television CS-13SX1 13" Stereo Monitor/Television CS-20SX1 20" Stereo Monitor/Television CS-20SX1 20" Stereo Monitor/Television CT-WN70R 6+1 Cassette Changer CT-WN70R 6+1 Cassette Changer


78


Pattern Match with LIKE and UPPER FunctionPattern Match with LIKE and UPPER Function

• SELECT product_code, product_descriptionSELECT product_code, product_descriptionFROM productsFROM productsWHERE UPPER(product_description) LIKE UPPER('%casset%');WHERE UPPER(product_description) LIKE UPPER('%casset%');

Changes to upper caseChanges to upper case

79


SQL> SQL> select product_code, product_descriptionselect product_code, product_description 2 2 from productsfrom products 3 3 where where upperupper(product_description) like (product_description) like upperupper('%casset%');('%casset%');

PRODUCT_CO PRODUCT_DESCRIPTIONPRODUCT_CO PRODUCT_DESCRIPTION---------- --------------------------------------------- -----------------------------------TC-KE400S Cassette DeckTC-KE400S Cassette DeckTC-KE500S Cassette DeckTC-KE500S Cassette DeckCT-W606DR Double Cassette DeckCT-W606DR Double Cassette DeckCT-W616DR Double Cassette DeckCT-W616DR Double Cassette DeckTD-W254 Double Auto-reverse Cassette DeckTD-W254 Double Auto-reverse Cassette DeckTD-W354 Double Auto-reverse Cassette DeckTD-W354 Double Auto-reverse Cassette DeckTD-W718 Dual Auto-reverse Rec Cassette DeckTD-W718 Dual Auto-reverse Rec Cassette DeckRS-TR373 Double Auto-reverse Cassette DeckRS-TR373 Double Auto-reverse Cassette DeckRS-TR575 Double Auto-reverse Cassette DeckRS-TR575 Double Auto-reverse Cassette DeckK-903 Dual Electronic Cassette DeckK-903 Dual Electronic Cassette DeckTC-WE405 Dual Cassette DeckTC-WE405 Dual Cassette DeckTC-WE605S Dual Auto-reverse Cassette DeckTC-WE605S Dual Auto-reverse Cassette Deck ••• •••K-90 Double Cassette DeckK-90 Double Cassette Deck


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SQL> select product_code, product_descriptionSQL> select product_code, product_description 2 from products2 from products 3 where product_description like '%casset%';3 where product_description like '%casset%';

no rows selectedno rows selected

Like WithLike Withoutout Matching the Case Matching the Case

CCassette assette ccassetteassetteCCassette assette ccassetteassette

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ORDER BY: Sorting the ResultsORDER BY: Sorting the Results

SELECT manufacturer_code, product_code, SELECT manufacturer_code, product_code, product_descriptionproduct_description


ORDER BY manufacturer_code, product_codeORDER BY manufacturer_code, product_code

Major (sort) keyMajor (sort) key Minor (sort) keyMinor (sort) key

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select manufacturer_code, product_code, product_descriptionselect manufacturer_code, product_code, product_description 2 2 from products order by manufacturer_code, product_code;from products order by manufacturer_code, product_code;

MAN PRODUCT_CO PRODUCT_DESCRIPTION MAN PRODUCT_CO PRODUCT_DESCRIPTION --- ---------- ------------------------------ --- ---------- ------------------------------ AIW NSX-D2 Mini Component System AIW NSX-D2 Mini Component System AIW XK-S9000 Cassette Deck AIW XK-S9000 Cassette Deck BOS 301-III Direct/Reflecting Speakers BOS 301-III Direct/Reflecting Speakers BOS 901Classic Direct/Reflecting Spkr System BOS 901Classic Direct/Reflecting Spkr System BOS AM3 Acoustimass Speaker System BOS AM3 Acoustimass Speaker System BOS AM5 Acoustimass 5 Speaker System BOS AM5 Acoustimass 5 Speaker System BOS AM7 Acoustimass 7 Speaker System BOS AM7 Acoustimass 7 Speaker System BOS VS-100 Center Channel Mini Speaker BOS VS-100 Center Channel Mini Speaker CRV AT-10 Loudspeakers CRV AT-10 Loudspeakers CRV AT-15 Three-way Speaker CRV AT-15 Three-way Speaker CRV SW-12B Subwoofer System CRV SW-12B Subwoofer System DA PS-6a Point Source Speaker System DA PS-6a Point Source Speaker System DA PS-8c Point Source Speaker Sytem DA PS-8c Point Source Speaker Sytem DA PS-9 Point Source Speaker System DA PS-9 Point Source Speaker System GMI PVX-31 Single Ch 31/3rd Octave Bands GMI PVX-31 Single Ch 31/3rd Octave Bands GMI XL-1800QII Prof Manual DJ Turntable GMI XL-1800QII Prof Manual DJ Turntable GMI XL-BD10 Semi-Auto Belt-Dr Turntable GMI XL-BD10 Semi-Auto Belt-Dr Turntable GMI XL-DD20 Semi-Automatic Turntable GMI XL-DD20 Semi-Automatic Turntable

......


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Using DISTINCTUsing DISTINCT

SELECT DISTINCT(manfuacturer_code)SELECT DISTINCT(manfuacturer_code)


Result:Result: The non-duplicated manufacturer_codes will be The non-duplicated manufacturer_codes will be retrieved.retrieved.

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select distinct(manufacturer_code) from products;select distinct(manufacturer_code) from products;

MAN MAN --- --- AIW AIW BOS BOS CRV CRV DA DA GMI GMI HVC HVC JBL JBL JVC JVC MIT MIT PAN PAN PIN PIN PIO PIO SAM SAM SHE SHE SON SON TEA TEA TEC TEC THN THN YAM YAM


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1 r. ching, ph.d. mis dept. california state university, sacramento week 4 september 19 relational...

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california state university

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relationcandidate key

relationprimary key

number of attributes

relation candidate

set of attributes

sacramento domain