Create a query to produce single output-er model, Database Management System

This assignment concerns the Research database. The database ER model is shown above, where attributes are omitted for clarity. The relational model for the database is:

Department(DeptNum, Descrip, Instname, DeptName, State, Postcode)

Academic(AcNum, DeptNum*, FamName, GiveName, Initials, Title)

Paper(PaNum, Title)

Author(PaNum*, AcNum*)

Field(FieldNum, ID, Title)

Interest(FieldNum*, AcNum*, Descrip)

DeptNum, AcNum, PaNum, and FieldNum are the identifiers of departments, academics, papers, and fields of interest respectively. Each Academic belongs to one Department and is the author of some (or no) Papers. Each Paper has at least one author. The table Fielddescribes areas of research work; each Academic works in some (or no) Fields, and may provide a description Descrip of their work.

The research database is used by the Department of Education, Science and Training of the Australian government on a regular basis to report on academic departments of education institutions. To this end, you are asked to write SQL queries, and present the report based on the output from your queries. Note that data inconsistency has been introduced during the data entry process, which you have to take care of in producing your report. It is known that the same state information may be represented in different ways. For example, Victoria may be kept as VIC, vic, or Vic. It is also known there are missing values for some attributes. For example, not all academic departments have their State information recorded in the database.

1. How many institutions contain the word "Technology" in their name. Your query must produce a single number as its output.

2. Make a list of academics that have more than five interests and have written or co-written less than ten papers. Use one IN construct and one EXISTS construct in your query. Output all details of the academics in the list.

3. Use a Set operator to create a list of academics who have written or co-written more than 5 papers and also have greater then 3 interests. List their academic number in the output.

4. Explain the following SQL query in English;

select givename, famname, instname

from academic natural join department

where acnum in

(select acnum

from author

where acnum not in

(select acnum

from interest

group by acnum))

and deptNum in (select deptNum

from academic

where deptname = 'Computer Science');

5. Find all the academics who have co-written a paper with academic number 151. Use only the Author table in a join query. You can use multiple instances of the table. The output should list the academic number of each co-author just once in the output. The output should not include academic number 151.

6. Write a query to find papers with more than five authors where the authors all come from different departments.

Posted Date: 3/19/2013 5:34:57 AM | Location : United States







Related Discussions:- Create a query to produce single output-er model, Assignment Help, Ask Question on Create a query to produce single output-er model, Get Answer, Expert's Help, Create a query to produce single output-er model Discussions

Write discussion on Create a query to produce single output-er model
Your posts are moderated
Related Questions
what is entity in database system?

what is Nested relational model? Explain with examples.

What are the several forms of identity? a) Value b) Name c) Built-in


Assume you are given a uniprocessor system with one gigabyte of memory and a 300 gigabyte disk. The OS on the machine has a demand paged virtual memory system with a local page rep

What are deadlocks?  How can they be avoided?  Ans: Deadlock considers to a particular condition when two or more processes are every waiting for another to release a resource,

What is a candidate key? Minimal super keys are known as candidate keys.

What is entity in DBMS? Entity: A DBMS entity is either a thing in the modelled world or a drawing element in an ERD.

Define Forms Based Interfaces? Forms-Based Interfaces - A forms-based interface display a form to each user. Forms are commonly designed and programmed for naive users and inte

Equi Join: A join in which the joining condition is based on equality among values in the common columns. Common columns show (redundantly) in the result table. Let us Consider th