Chapter 4, Problem 10SCG

Program Plan Intro

“SELECT” command:

The “SELECT” command is used to retrieve data in a database.

Syntax for selecting values from the table is as follows:

SELECT STUDENT_ID FROM STUDENT;

• The given query is used to display each student ID from “STUDENT” table.

Naming the computed column in SQL:

• User can assign a name to the computation by using below ways:
  • Name the computation with the word “AS”.
  • User desired name.

Example:

The example for naming the computed column in SQL is shown below:

SELECT STUDENT_ID, STUDENT_NAME, MAXIMUM_LIMIT – SCORE AS STUDENT_CREDIT FROM STUDENT;

The above query is used to display student id, student name and student credit from “STUDENT” table.

STUDENT_ID	STUDENT_NAME	STUDENT_CREDIT
123	Merry	90
208	John	86
408	Rose	98
564	Joseph	78

Explanation:

• User can compute the student credit using the expression “MAXIMUM_LIMIT – SCORE”.
• From the given query, the computation is calculated by using “-” operator that is from “MAXIMUM_LIMIT – SCORE”.
• Here the computed result is name as “STUDENT_CREDIT” by using the word “AS”.