Chapter 4, Problem 10RQ

Program Plan Intro

“ORDER BY” Clause:

• User can sort the data in specific order using “ORDER BY” clause.
• The column on which to sort data is called a sort key or a simple key.
• To sort the output, use an “ORDER BY” clause followed by the sort key.
• If the user does not specify a sort order, the output displayed in default order that is ascending order.

Example:

The example for “ORDER BY” clause is given below:

SELECT STUDENT_ID, STUDENT_NAME, STUDENT_CREDIT FROM STUDENT ORDER BY STUDENT_CREDIT;

Explanation:

The above query is used to list student ID, name and credit for each student with ascending order of student credit using an “ORDER BY” clause.

• From the given query, the sort key is “STUDENT_CREDIT”. So, the rows are sorted in ascending order by “STUDENT_CREDIT”.

Explanation of Solution

Most important key:

• The more important column is called the most important key.
• It is also called as the major sort key or the primary sort key.

Example:

The example for most important key is given below:

SELECT STUDENT_ID, STUDENT_NAME, STUDENT_CREDIT FROM STUDENT ORDER B...

Explanation of Solution

Less important key:

• The less important column is called the most important key.
• It is also called as the minor sort key or the secondary sort key.

Example:

The example for less important key is given below:

SELECT STUDENT_ID, STUDENT_NAME, STUDENT_CREDIT FROM STUDENT ORDER...