Conceptual DesignConceptual Design
Modeling the rules of organizationModeling the rules of organization Building ER modelBuilding ER model
Penyewaan BukuPenyewaan BukuBusiness RulesBusiness Rules1.1. Seorang ANGGOTA boleh meminjam Seorang ANGGOTA boleh meminjam
lebih dari satu BUKUlebih dari satu BUKU2.2. Satu jenis BUKU memiliki lebih dari Satu jenis BUKU memiliki lebih dari
satu salinansatu salinan3.3. Beberapa ANGGOTA boleh meminjam Beberapa ANGGOTA boleh meminjam
satu atau lebih jenis BUKU yang satu atau lebih jenis BUKU yang samasama
4.4. Untuk setiap PEMINJAMAN harus Untuk setiap PEMINJAMAN harus dikembalikan tepat pada waktunya, dikembalikan tepat pada waktunya, jika tidak akan dikenakan dendajika tidak akan dikenakan denda
ER Model ER Model Penyewaan BukuPenyewaan Buku
ANGGOTA
Id_Anggota
BUKU
Id_Buku
Jumlah_Salinan
PEMINJAMAN
Id_Peminjaman
Id_Buku
Id_Anggota
Tgl_Pinjam
Tgl_HrsKembali
Tgl_Kembali
Denda
has has
Tempat KursusTempat KursusBusiness RulesBusiness Rules1.1. Seorang SISWA boleh mengambil Seorang SISWA boleh mengambil
satu atau lebih KELASsatu atau lebih KELAS2.2. Satu KELAS terdiri dari satu atau Satu KELAS terdiri dari satu atau
banyak SISWAbanyak SISWA3.3. Satu GURU boleh mengajar di Satu GURU boleh mengajar di
satu atau banyak KELASsatu atau banyak KELAS4.4. Satu RUANGAN dapat digunakan Satu RUANGAN dapat digunakan
oleh satu atau banyak KELASoleh satu atau banyak KELAS
ER Model Tempat ER Model Tempat KursusKursus
SISWA
Id_Siswa
GURU
Id_GURU
KELAS
Id_Kelas
has has
RUANGAN
Id_Ruangan
has
A hospital in-patient systemA hospital in-patient systemBusiness RulesBusiness Rules
A A hospitalhospital is organised into a number of is organised into a number of wardswards.. Each Each wardward has a has a ward numberward number and a and a namename recorded, along recorded, along
with a number of beds in that ward.with a number of beds in that ward. Each Each wardward is staffed by is staffed by nursesnurses.. NursesNurses have their have their staff numberstaff number and and namename recorded, and are recorded, and are
assigned to a single ward.assigned to a single ward. Each Each patientpatient in the hospital has a in the hospital has a patient identification patient identification
numbernumber, and their , and their namename, , addressaddress and and date of birthdate of birth are are recorded.recorded.
Each Each patientpatient is under the care of a single is under the care of a single consultantconsultant and is and is assigned to a single assigned to a single wardward..
Each Each consultantconsultant is responsible for a number of is responsible for a number of patientspatients.. ConsultantsConsultants have their have their staff numberstaff number, , namename and and specialismspecialism
recorded.recorded.
Exercise on In-patient systemExercise on In-patient system
1.1. State 4 entities for the system giving a suitable State 4 entities for the system giving a suitable identifier for each entity. identifier for each entity. ward, nurse, patient, ward, nurse, patient, consultantconsultant
2.2. Draw an entity-relationship diagram to show the Draw an entity-relationship diagram to show the relationships between the entities.relationships between the entities.
Hospital In-Patient’s Hospital In-Patient’s ER ModelER Model
WARD
Ward_Id
NumberOfBeds
PATIENT
Patient_Id
Patient_Name
Patient_Address
Patient_DoB
NURSE
Staff_No
Nurse_Name
Staffed by
CONSULTANT
Staff_No
Consultant_Name
Consultant_Spc
has
has
99
The Enhanced E-R The Enhanced E-R Model andModel andBusiness RulesBusiness RulesModern Database Modern Database
ManagementManagement
66thth Edition EditionJeffrey A. Hoffer, Mary B. Prescott, Jeffrey A. Hoffer, Mary B. Prescott,
Fred R. McFaddenFred R. McFadden
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Supertypes and Supertypes and SubtypesSubtypes Subtype:Subtype: A subgrouping of the entities in an A subgrouping of the entities in an
entity type which has attributes that are entity type which has attributes that are distinct from those in other subgroupingsdistinct from those in other subgroupings
Supertype:Supertype: An generic entity type that has An generic entity type that has a relationship with one or more subtypesa relationship with one or more subtypes
Inheritance:Inheritance:– Subtype entities inherit values of all Subtype entities inherit values of all
attributes of the supertypeattributes of the supertype– An instance of a subtype is also an instance An instance of a subtype is also an instance
of the supertypeof the supertype
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Figure 4-1Basic notation for
supertype/subtype relationships
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Figure 4-2 -- Employee supertype with three subtypes
All employee subtypes will have emp nbr, name, address, and date-hired
Each employee subtype will also have its own attributes
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Relationships and Relationships and SubtypesSubtypes Relationships at the Relationships at the supertypesupertype
level indicate that all subtypes level indicate that all subtypes will participate in the relationshipwill participate in the relationship
The instances of a The instances of a subtypesubtype may may participate in a relationship participate in a relationship unique to that subtype. In this unique to that subtype. In this situation, the relationship is situation, the relationship is shown at the subtype levelshown at the subtype level
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Figure 4-3 -- Supertype/subtype relationships in a hospital
Both outpatients and resident patients are cared for by a responsible physician
Only resident patients are assigned to a bed
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Generalization and Generalization and SpecializationSpecialization Generalization:Generalization: The process of The process of
defining a more general entity type defining a more general entity type from a set of more specialized entity from a set of more specialized entity types. types. BOTTOM-UPBOTTOM-UP
Specialization:Specialization: The process of The process of defining one or more subtypes of the defining one or more subtypes of the supertype, and forming supertype, and forming supertype/subtype relationships. supertype/subtype relationships. TOP-TOP-DOWNDOWN
1616
Figure 4-4 – Example of generalization
(a) Three entity types: CAR, TRUCK, and MOTORCYCLE
All these types of vehicles have common attributes
1717
Figure 4-4(b) – Generalization to VEHICLE supertype
So we put the shared attributes in a supertype
Note: no subtype for motorcycle, since it has no unique attributes
1818
Figure 4-5 – Example of specialization
(a) Entity type PART
Only applies to manufactured
parts
Applies only to purchased parts
1919
Figure 4-5(b) – Specialization to MANUFACTURED PART and PURCHASED PART
Note: multivalued attribute was replaced by a relationship to another entity
Created 2 subtypes
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Constraints in Constraints in Supertype/ Supertype/ Completeness Completeness ConstraintConstraint
Completeness ConstraintsCompleteness Constraints: Whether : Whether an instance of a supertype an instance of a supertype mustmust also be a also be a member of at least one subtypemember of at least one subtype– Total Specialization Rule: Yes (double line)Total Specialization Rule: Yes (double line)– Partial Specialization Rule: No (single line)Partial Specialization Rule: No (single line)
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Figure 4-6 – Examples of completeness constraints
(a) Total specialization rule
A patient must be either an outpatient or a resident patient
2222
Figure 4-6(b) – Partial specialization rule
A vehicle could be a car, a truck, or neither
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Constraints in Constraints in Supertype/ Supertype/ Disjointness constraintDisjointness constraint Disjointness ConstraintsDisjointness Constraints: :
Whether an instance of a supertype Whether an instance of a supertype may may simultaneouslysimultaneously be a member of be a member of two (or more) subtypes.two (or more) subtypes.– Disjoint Rule: An instance of the supertype Disjoint Rule: An instance of the supertype
can be only ONE of the subtypescan be only ONE of the subtypes– Overlap Rule: An instance of the Overlap Rule: An instance of the
supertype could be more than one of the supertype could be more than one of the subtypessubtypes
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(a) Disjoint rule
Figure 4-7 – Examples of disjointness constraints
A patient can either be outpatient or resident, but not both
2525
Figure 4-7(b) Overlap rule
A part may be both purchased and manufactured
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Constraints in Constraints in Supertype/ Subtype Supertype/ Subtype DiscriminatorsDiscriminators Subtype DiscriminatorSubtype Discriminator:: An An
attribute of the supertype whose values attribute of the supertype whose values determine the target subtype(s)determine the target subtype(s)– DisjointDisjoint – a – a simplesimple attribute with alternative attribute with alternative
values to indicate the possible subtypesvalues to indicate the possible subtypes– OverlappingOverlapping – a – a compositecomposite attribute whose attribute whose
subparts pertain to different subtypes. Each subparts pertain to different subtypes. Each subpart contains a boolean value to indicate subpart contains a boolean value to indicate whether or not the instance belongs to the whether or not the instance belongs to the associated subtypeassociated subtype
2727
Figure 4-8 – Introducing a subtype discriminator (disjoint rule)
A simple attribute with different possible values indicating the subtype
2828
Figure 4-9 – Subtype discriminator (overlap rule)
A composite attribute with sub-attributes indicating “yes” or “no” to determine whether it is of each subtype
2929
Figure 4-10 – Example of supertype/subtype hierarchy
PRPR
Kasus Rumah Sakit:Kasus Rumah Sakit:
1.1. Definisikan Business Rules-nya!Definisikan Business Rules-nya!
2.2. Buatlah ER diagram untuk kasus Buatlah ER diagram untuk kasus tersebut dimana didalamnya tersebut dimana didalamnya terdapat completeness terdapat completeness constraints, disjointness constraints, disjointness constraints, subtype constraints, subtype discriminator.discriminator.
Bersambung minggu depan…….Bersambung minggu depan…….
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Entity ClustersEntity Clusters EER diagrams are difficult to read EER diagrams are difficult to read
when there are too many entities and when there are too many entities and relationshipsrelationships
Solution: group entities and Solution: group entities and relationships into relationships into entity clustersentity clusters
Entity clusterEntity cluster: set of one or more : set of one or more entity types and associated entity types and associated relationships grouped into a single relationships grouped into a single abstract entity typeabstract entity type
3333
Figure 4-13(a) – Possible entity clusters
for Pine Valley Furniture
Related groups of entities could become clusters
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Figure 4-13(b) – EER diagram of PVF entity clusters
More readable, isn’t it?
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Business rulesBusiness rules
Statements that Statements that definedefine or or constrainconstrain some some aspect of the business.aspect of the business.
Constraints can impact:Constraints can impact:– Structure (definition, domain, relationship)Structure (definition, domain, relationship)– Behavior (operational constraints)Behavior (operational constraints)
Classification of business rules:Classification of business rules:– Derivation – rule derived from other knowledgeDerivation – rule derived from other knowledge– Structural assertion – rule expressing static Structural assertion – rule expressing static
structurestructure– Action assertion – rule expressing Action assertion – rule expressing
constraints/control of organizational actionsconstraints/control of organizational actions
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Figure 4-15 – EER depiction of
business rules classification
Source: adapted from GUIDE Business Rules Project, 1997.
3737
Action Assertion Action Assertion ClassificationsClassifications ResultResult
– Condition – IF/THEN ruleCondition – IF/THEN rule– Integrity constraint – must always be trueIntegrity constraint – must always be true– Authorization – privilege statementAuthorization – privilege statement
FormForm– Enabler – leads to creation of new objectEnabler – leads to creation of new object– Timer – allows or disallows an actionTimer – allows or disallows an action– Executive – executes one or more actionsExecutive – executes one or more actions
RigorRigor– Controlling – something must or must not Controlling – something must or must not
happenhappen– Influencing – guideline for which a notification Influencing – guideline for which a notification
must occurmust occur
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Stating an Action Stating an Action AssertionAssertion
Anchor ObjectAnchor Object – an object on which – an object on which actions are limitedactions are limited
ActionAction – creation, deletion, update, – creation, deletion, update, or reador read
Corresponding ObjectsCorresponding Objects – an object – an object influencing the ability to perform an influencing the ability to perform an action on another business ruleaction on another business rule
Action assertion will identify corresponding objects that Action assertion will identify corresponding objects that constrain the ability to perform actions on anchor objectsconstrain the ability to perform actions on anchor objects
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Figure 4-16 – Data model segment for class scheduling
4040
Figure 4-17 – Business Rule 1: For a faculty member to be assigned to teach a section of a course, the faculty member must be qualified to teach the course for which that section is scheduled
Action assertion
Anchor object
Corresponding object
Corresponding object
In this case, the action assertion
is a RRestriction
4141
Figure 4-18 –Business Rule 2: For a faculty member to be assigned to teach a section of a course, the faculty member must not be assigned to teach a total of more than three course sections
Action assertionAnchor object
Corresponding object
In this case, the action assertion is an
UUpper LIMLIMit