Problem

Add minimum and maximum cardinality notation to each of the following figures, as approp...

Add minimum and maximum cardinality notation to each of the following figures, as appropriate:

a. Figure 2-5

b. Figure 2-10a

c. Figure 2-11b

d. Figure 2-12 (all parts)

e. Figure 2-13c

f. Figure 2-14

Figure 2-11b

FIGURE 2-13 Representing a bill-of-materials structure

Step-by-Step Solution

Solution 1

Add minimum and maximum cardinality notation

a) Cardinality notation for example of weak entity and its identifying relationship:

The E-R diagram for weak entity and its identifying relationship contains the two entity types such as EMPLOYEE and DEPENDENT.

• The entity “EMPLOYEE” is a strong entity and the entity “DEPENDENT” is a weak entity denoted by the double lined rectangle with the relationship of its owner.

o Here, “Carries” is an identifying relationship between the “EMPLOYEE” and “DEPENDENT” entities.

• The cardinality relationship is “mandatory one” for entity “EMPOLYEE” and “optional many” for entity “DEPENDENT”.

o This is because, an employee carries zero or more dependents and a dependent may or may not be carried by one employee.

• The cardinality relationship representation of E-R diagram (Figure 2-5) is shown below:

10943-2-11E_fig1.jpg

b) Cardinality notation for example of relationship type:

• The E-R diagram contains the two entities are “EMPLOYEE” and “COURSE”.

o Here, “Completes” is a relationship between the “EMPLOYEE” and “COURSE” entities.

• The cardinality relationship is “Optional many” for entity “EMPOLYEE” and “optional many” for entity “COURSE”.

o This is because, an employee may or may not complete one or more course and a course may or may not be completed by one or more employee.

• The cardinality relationship representation of E-R diagram (Figure 2-10a) is shown below:

10943-2-11E_fig2.jpg

c) Cardinality notation for example of associative entity:

• The E-R diagram contains the two entities are “EMPLOYEE” and “COURSE” with associative entity “CERTIFICATE”.

• The cardinality relationship between entity “EMPLOYEE” and associative entity “CERTIFICATE” is “Mandatory one to Optional many”.

• The cardinality relationship between associative entity “CERTIFICATE” and entity “EMPLOYEE” is Optional many to Mandatory one.

o This is because, one employee may have more than one certificate and a course entity can have more than one certificate for different employees.

• The cardinality relationship representation of E-R diagram (Figure 2-11b) is shown below:

10943-2-11E_fig3.jpg

d) Cardinality notation for example of relationship of different degrees:

One-to-one unary relationships:

The E-R diagram contains the entity is “PERSON” with unary relationship “Is Married To”.

• The “Optional one” cardinality relationship exists for the entity “PERSON”.

o This is because; a person may or may not marry a person.

• The cardinality relationship representation of E-R diagram (Figure 2-12a) is shown below:

C:\Users\300889\AppData\Local\Microsoft\Windows\Temporary Internet Files\Content.Outlook\XNEWY8E1\10943-2-11E_fig13.jpg

One-to-many unary relationships:

The E-R diagram contains the entity is “EMPLOYEE” with unary relationship “Manages”.

• The cardinality relationship of entity “PERSON” is “Mandatory one to Optional many”.

o This is because, an Employee may manage one or more features. One work can be managed by one or more employees.

• The cardinality relationship representation of E-R diagram(Figure 2-12a) is shown below:

10943-2-11E_fig5.jpg

One-to-one unary relationships:

The E-R diagram contains the entity is “TEAM” with unary relationship “Stands After”.

• The cardinality relationship of entity “TEAM” is “Mandatory one to Mandatory one”.

o This is because; a team may or may not stand for team.

• The cardinality relationship representation of E-R diagram(Figure 2-12a) is shown below:

C:\Users\300889\AppData\Local\Microsoft\Windows\Temporary Internet Files\Content.Outlook\XNEWY8E1\10943-2-11E_fig14.jpg

One-to-one binary relationships:

The E-R diagram contains the two entities is “EMPLOYEE” and “PARKING SPACE” with binary relationship “Is Assigned”.

• The Optional one cardinality relationship exists between the entities “EMPLOYEE” and “PARKING SPACE”.

o An employee may or may not be assigned to one parking place.

• The cardinality relationship representation of E-R diagram(Figure 2-12b) is shown below:

10943-2-11E_fig7.jpg

One-to-many binary relationships:

The E-R diagram contains the two entities is “PRODUCT LINE” and “PRODUCT” with binary relationship “Contains”.

• The entity “PRODUCT” will be related to minimum of one product line entity. So the cardinality is “Mandatory one” is applicable.

• The entity “PRODUCT LINE” has one cardinality constraint notation. The number of products can be related to number of product lines. So, the cardinality is “Mandatory more” is applicable.

• The cardinality relationship between entities “PRODUCT” and “PRODUCT LINE” is “Mandatory one to Mandatory many”.

o This is because, a product line must contain one or more product and one or more products must contain one product line.

• The cardinality relationship representation of E-R diagram(Figure 2-12b) is shown below:

10943-2-11E_fig8.jpg

Many-to-many binary relationships:

The E-R diagram contains the two entities is “STUDENT” and “COURSE” with binary relationship “Register For”.

• The cardinality relationship between entities “STUDENT” and “COURSE” is “Optional many to Optional many”.

o This is because, a student may be registered for more than one course and a number of courses can be registered by number of students.

• The cardinality relationship representation of E-R diagram(Figure 2-12b) is shown below:

10943-2-11E_fig9.jpg

Ternary relationship:

The E-R diagram contains the three entities is “VENDOR”, “WAREHOUSE”, and “PART” with ternary relationship “Supplies”.

• The cardinality relationship between entities “VENDOR”, “WAREHOUSE”, and “PART” is “Mandatory many is optional many”.

o This is because; vendor may or may not supply the parts into warehouse.

• The cardinality relationship representation of E-R diagram(Figure 2-12c) is shown below:

C:\Users\300889\AppData\Local\Microsoft\Windows\Temporary Internet Files\Content.Outlook\XNEWY8E1\10943-2-11E_fig15.jpg

e) Cardinality notation for bill-of-material structure with associative entity:

• The E-R diagram contains the two entities are “ITEM” and “BOM STRUCTURE” with two relationships “Has Component” and “Used In Assemblies”.

• For one relationship:

o The cardinality relationship between entity “ITEM” and associative entity “BOM STRUCTURE” is “Mandatory one to Optional many”.

• This is because; one or more Item may or may not have components for one or more bom structure.

• For another relationship:

o The cardinality relationship between entity “ITEM” and associative entity “BOM STRUCTURE” is “Mandatory one to Optional many”.

• This is because, one or more item may or may not be used in assemblies for one or more bom structure.

• The cardinality relationship representation of E-R diagram(Figure 2-13c) is shown below:

10943-2-11E_fig11.jpg

f) Cardinality notation for ternary relationship with associative entity:

• The E-R diagram contains the three entities are “VENDOR”, “PART”, and “WAREHOUSE” with associative entity “SUPPLY SCHEDULE”.

o “PART”, “VENDOR”, and “WAREHOUSE” that are associated with an associative entity called “SUPPLY SCHEDULE”.

o The cardinality relationship between three entities with associative entity is “Optional many to Mandatory one”.

• The cardinality relationship representation of E-R diagram(Figure 2-14) is shown below:

10943-2-11E_fig12.jpg

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