Students enrolled in DCIT 214 Information Modeling can use a programming homework service to help complete challenging assignments on database design and SQL queries. Programming homework services employ tutors skilled in entity-relationship diagramming and normalization who can provide examples and explanations when information modeling assignments involve complex data structures.Qn. 1
Assuming suitable entity types and reference modes are understood, which of the following sentences fit our standard pattern for expressing exactly one elementary fact?
- Adam likes Eve. [Elementary facts]
- Bob does not like John.
- Tom visited Los Angeles and New York. (can be split into 2 facts)
- Tom visited Los Angeles or New York.
- If Tom visited Los Angeles then he visited New York.
- Sue is funny. [Elementary facts]
- All people are funny.
- Some people in New York have toured Australia.
- Brisbane and Sydney are in Australia.
- Brisbane and Sydney are in the same country.
- Who does Adam like? (not a fact, just a question)
For an elementary fact to exist, a given object must play a given property (role), or at least one object takes part in a relationship (Halpin & Morgan, 2010). Elementary facts should not be those that can be fragmented into reduced sub-units of facts “with the same objects”; thus, use neither logical quantifiers [some, all, etc.] nor logical connectives [if, or, not, and, etc.] (Halpin & Morgan, 2010). Sentences (2-5) and (7-10) all contain these quantifiers and connectives. Similarly, sentence (11) does not qualify to be a fact. Thus, only sentences (1) and (6) are elementary facts.
Qn. 2
Indicate at least two different meanings for each of the following sentences, by including names for object types and reference modes.
The sentences below are ambiguous and thus subject to misinterpretation (Halpin & Morgan, 2010). Therefore, the object or entity types that start in capital letters need to be added to eradicate referential ambiguity, as shown below.
- Pluto is owned by Mickey.
Planet (.name) ‘Pluto’ is owned by Galaxy (.name) ‘Mickey’.
Animal (.name) ‘Pluto’ is owned by Person (.name) ‘Mickey’.
- Dallas is smaller than Sydney.
Person (.name) ‘Dallas’ is smaller than Person (.name) ‘Sydney’.
City (.name) ‘Dallas’ is smaller than City (.name) ‘Sydney’.
- Arnold can lift 300.
Person (.name) ‘Arnold’ can lift Weight (.nr) 300.
Person (.name) ‘Arnold’ can lift Quantity of Pounds (lb:) 300.
Perform step 1 of the CSDP for the following output reports. In verbalizing the facts, you may restrict yourself to the top row of the table unless another row reveals a different kind of fact.
Athlete | Height (cm) |
Jones EM | 166 |
Pie QT | 166 |
Smith JA | 175 |
Athlete | Height (cm) |
Jones EM | 400 |
Pie QT | 450 |
Smith JA | 550 |
Person | Height (cm) | Year |
Jones EM | 166 | 1955 |
Pie QT | 160 | 1970 |
Smith JA | 175 | 1955 |
Person | Height (cm) | Year |
Jones EM | 160 | 1970 |
166 | 1980 | |
166 | 1990 |
Advisory panel | Internal member | External member |
Databases | Codd | Ienshtein |
Kowalski | Spock | |
Logic programming | Colmerauer | Robinson |
Kowalski | ||
Spock |
Advisory Panel (.name) ‘Databases’ has External Member (.name) ‘Ienshtein’.
Student Nr | Course | Rating |
1001 | CS112 | 7 |
1001 | CS100 | 6 |
1002 | CSl12 | 4 |
1003 | CS100 | 7 |
1003 | CSl12 | 4 |
1003 | MP104 | 4 |
Parents | Children |
Ann, Bill | Colin, David, Eve |
David, Fiona | Gus |
Parents (.name) ‘Ann, Bill’ have Child (.name) ‘David’.
Parents (.name) ‘Ann, Bill’ have Child (.name) ‘Eve’
Country | Friends | Enemies |
Disland | Oz | |
Hades | Oz | |
Wundrland | ||
Wundrland | Oz | Hades |
Oz | Disland | Hades |
Wundrland |
Country (.name) ‘Wundrland’ has Enemies (.name) ‘Hades’.
Apple | Australia | June, July, August |
America | Oct, Dec, Jan | |
Ireland | Oct, Dec | |
Mango | Australia | Nov, Dec, Jan, Feb |
Pineapple | America | June, July |
Australia | Oct, Nov, Dec, Jan |
Country (.name) ‘Australia’ produces Fruit (.name) ‘Apple’ in Month (.name) ‘July’.
Country (.name) ‘Australia’ produces Fruit (.name) ‘Apple’ in Month (.name) ‘August’.
Reference
Halpin, T., & Morgan, T. (2010). Information modeling and relational databases. Morgan Kaufmann.