Computers and Technology, 13.07.2021 19:40 hammackkatelyn60

Consider the following schema: SUPPLIERS (SID: integer, SNAME: string, STREET: string, CITY: string, ZIP: string) PARTS (PID: integer, PNAME: string, COLOR: string) CATALOG (SID: integer, PID: integer, COST: real)
The primary key attributes are underlined, and the domain of each attribute is listed after the attribute name. Thus, SID is the primary key for SUPPLIERS, PID is the primary key for PARTS, and SID and PID together form the primary key for CATALOG. Attribute SID in CATALOG is a foreign key that refers to the primary key SID of SUPPLIERS and PID in CATALOG is a foreign key that refers to the primary key PID of PARTS. The CATALOG relation lists the prices charged for parts by suppliers.
State what the following query computes.
0. πCITY (πPID (σ COLOR = 'green' (PARTS) ) * σ COST>50 (CATALOG) * πSID, CITY (SUPPLIERS) )
Write the following queries in relational algebra.
1. Find the names of parts for which there is some supplier
2. Find the names of parts supplied by suppliers who are at 1 Central Ave.
3. Find the names of suppliers who supply some red part.
4. Find the SIDs of suppliers who supply some red or green part.
5. Find the SID of suppliers who supply some red part or whose address is '221 Packer Street'.
6. Find the SIDs of suppliers who supply some red part and some green part.
7. Find the PIDs of parts that are red or are supplied by a supplier who is at the city of Newark.
8. Find the PIDs of parts supplied by a supplier who is at the city of Newark and by a supplier who is at the city of Trenton.
9. Find the PIDs of parts supplied by every supplier.
10. Find the PIDs of parts supplied by every supplier who supplies at least one part.
11. Find the SIDs of suppliers who supply at least two different parts (you are not allowed to use a grouping/aggregation operation for this query).
12. Find the SIDs of suppliers who supply at least two different parts (you have to use a grouping/aggregation operation for this query).
13. For every part, find its PID, its PNAME and the number of suppliers who sell it.
14. List the PID, PNAME and average cost of all parts.
15. Find the average cost of red parts.
16. Find the average cost of parts supplied by suppliers named 'Yosemite Sham'.

Answers: 2

Show answers

Another question on Computers and Technology

Computers and Technology, 22.06.2019 10:30

You are almost finished updating a web site. as part of the update, you have converted all pages from html 4.0 to html5. the project is currently on schedule. however, your project manager has been asked by the marketing team manager to justify a day of time spent validating the site's html5 pages. the marketing team manager does not have technical knowledge of the internet or the web. which is the most appropriate explanation to provide to the marketing team manager?

Answers: 1

Answer

Computers and Technology, 22.06.2019 17:30

Working on this program in python 3.7: a year in the modern gregorian calendar consists of 365 days. in reality, the earth takes longer to rotate around the sun. to account for the difference in time, every 4 years, a leap year takes place. a leap year is when a year has 366 days: an extra day, february 29th. the requirements for a given year to be a leap year are: 1) the year must be divisible by 42) if the year is a century year (1700, 1800, the year must be evenly divisible by 400some example leap years are 1600, 1712, and 2016.write a program that takes in a year and determines whether that year is a leap year.ex: if the input is 1712, the output is: 1712 is a leap year. ex: if the input is 1913, the output is: 1913 is not a leap year. your program must define and call the function isleapyear(useryear). the function should return true if the input year is a leap year and false otherwise.

Answers: 1

Answer

Computers and Technology, 23.06.2019 06:30

On early television stations, what typically filled the screen from around 11pm until 6am? test dummies test patterns tests testing colors

Answers: 1

Answer

Computers and Technology, 23.06.2019 23:40

4. what is the reason for including the following code snippet in the header file animal.h? #ifndef animal_h #define animal_h class animal { public: animal(); animal(double new_area_hunt); void birth(); void hunt(double new_area_hunt); void death(); double get_area_hunt() const; private: double area_hunt; }; #endif

Answers: 3

Answer

You know the right answer?

Consider the following schema: SUPPLIERS (SID: integer, SNAME: string, STREET: string, CITY: string...

Questions