Review Session Quiz 1 · 2017. 10. 15. · Entity Relationship Diagrams Basic Terms and Concepts 1.Entities 2.Relationships Design Constraints 1.Entity Sets vs Attributes 2.Entity

ReviewSessionQuiz1

DifferentTopicsCoveredatthisPoint

• RelationalAlgebra• RelationalModel• Entity-RelationshipModel• TupleRelationalCalculus(Notontest)• Sql 1• Sql 2• Constraints

RelationalAlgebra

BasicOperators1.Select(σ)2.Project(π)3.Union(∪)4.Setdifference(–)5.Cartesianproduct(X)6.Rename(ρ)

AdvancedOperators1.NaturalJoin(⨝)2.Division(÷)3.Aggregation(g)4.OuterJoins(⟕⟗⟖)

ExampleQuestion

ExampleQuestion

ExampleQuestion2

QuestionsonRelationalAlgebra?

BasicOperators1.Select(σ)2.Project(π)3.Union(∪)4.Setdifference(–)5.Cartesianproduct(X)6.Rename(ρ)

AdvancedOperators1.NaturalJoin(⨝)2.Division(÷)3.Aggregation(g)4.OuterJoins(⟕⟗⟖)

EntityRelationshipDiagrams

BasicTermsandConcepts1. Entities2. RelationshipsDesignConstraints1. EntitySetsvsAttributes2. EntitySetsvsRelationshipSets3. RelationshipCardinalities4. WeakEntitySets5. Inheritance

Typesofkeys1.CandidateKeys2.SuperKeys3.PrimaryKeys

TranslatingERDiagramsToRelationalSets

QuestionsonTupleRelationalCalculus?

FormulaSetup:1. Queryhastheform:{T|p(T)}2. AnsweristhesetofalltuplesT

forwhichtheformulap(T)evaluatestotrue.

AvailableOperations1. ¬p,p∨ q,p∧q

1. PandQareformulas

2. ∃R(p(R))1. Risatuplevariable

3. ∀R(p(R))1. Risatuplevariable

SQL

• BasicStructure

• OtherIdeas• DistinctClause• NaturalJoin• RenameOperator• AggregateFunctions

• GroupBy• NestedSubQueries

ExampleQuestion

ExampleQuestion

ExampleQuestion

ExampleQuestionCont.

• Breaktheproblemupintosubparts

Constraints

IntegrityConstraints1.PrimaryKey2.AttributeConstraint3.ReferentialIntegrityConstraint4.GlobalConstraints