[cswtsjaij]

Can someone PLEASE help me with the three problems below:

1. Write a simple subquery and display the course_no, description, cost for the course with the lowest course cost.

2. Write a correlated subquery and display the student_id, last_name,first_name of students enrolled in three or more classes.
a. Use the EXISTS or NOT EXISTs operator Hint: The HAVING clause can be used as well
b. Use the IN operator in a subquery

3. Write a correlated subquery and display the instructor_id, first_name, last_name, zip columns from the instructor table where the zip code is NULL.
a. Use the NOT EXISTs operator
b. Use the NOT IN operator

[Nova Dragoon]

can you show us what you've done so far?

[cswtsjaij]

Nova Dragoon, on 5 Aug, 2006 - 10:57 AM, said:

can you show us what you've done so far?

For problem #1 I have:

SELECT course_no, description
FROM COURSE
WHERE cost < ANY
(SELECT cost
FROM COURSE);

For problem #2 and #3 I don't have anything. I am not sure how to execute these two problems. I am a beginner using SQL.

[Amadeus]

Can you post the table schema as well? (A list of the fields in the database table, and their field types).

[cswtsjaij]

Amadeus, on 5 Aug, 2006 - 11:40 AM, said:

Can you post the table schema as well? (A list of the fields in the database table, and their field types).

I think the attached file is the table schema.

Attached File(s)

•  schemaDiagramV04.zip (49.08K)
  Number of downloads: 86

[Jayman]

For the first one, you need to look at using the MIN command in your subquery.

This might help you.

**edit: fixed my bad grammer just for you Xenon

This post has been edited by jayman9: 05 August 2006 - 12:49 PM

[cswtsjaij]

jayman9, on 5 Aug, 2006 - 12:38 PM, said:

For the first one, you need to look at using the MIN command in your subquery.

This might help you.

**edit: fixed my bad grammer just for you Xenon

Where do I place the MIN command in my subquery?

[Jayman]

Did you look at the link I gave you, it gives examples?

But would look like this:

SELECT course_no, description, cost
FROM COURSE
WHERE cost =
(SELECT MIN(cost)
FROM COURSE);

This post has been edited by jayman9: 05 August 2006 - 03:54 PM

[cswtsjaij]

jayman9, on 5 Aug, 2006 - 03:53 PM, said:

Did you look at the link I gave you, it gives examples?

But would look like this:

SELECT course_no, description, cost
FROM COURSE
WHERE cost =
(SELECT MIN(cost)
FROM COURSE);

THANKS. How would I go about doing problems #2 and #3?

[Jayman]

http://www.plus2net....al/site_map.php
You can find all the information you need at this site.