A Guide to SQL
A Guide to SQL
9th Edition
ISBN: 9781337668880
Author: Pratt
Publisher: Cengage
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Chapter 4, Problem 9CAT
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.

“COUNT” function:

  • It is the one function of aggregate function.
  • The “COUNT” function is used to compute the number of rows in a table.

Example:

The example for “COUNT” function is given below:

SELECT COUNT(*) FROM STUDENT WHERE MARK_CREDIT >= 90;

The above query is used to display the number of students whose mark credit is greater or equal to “90” by using “COUNT” function.

  • From the given query, the asterisk (*) represent any column.
  • User can also count the number of rows in a query by selecting a particular column instead of using the asterisk.
    • The below example is as follows

      SELECT COUNT(STUDENT_ID) FROM STUDENT WHERE MARK_CREDIT >= 90;

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Need help answering these questions!1. Design a While loop that lets the user enter a number. The number should be multiplied by 10, and the result stored in a variable named product. The loop should iterate as long as the product contains a value less than 100.   2. Design a For loop that displays the following set of numbers: 0, 10, 20, 30, 40, 50 . . . 1000   3. Convert the While loop in the following code to a Do-While loop:     Declare Integer x = 1     While x > 0        Display "Enter a number."        Input x     End While
Need help with these:Design a While loop that lets the user enter a number. The number should be multiplied by 10, and the result stored in a variable named product. The loop should iterate as long as the product contains a value less than 100.   2. Design a For loop that displays the following set of numbers: 0, 10, 20, 30, 40, 50 . . . 1000   3. Convert the While loop in the following code to a Do-While loop:     Declare Integer x = 1     While x > 0        Display "Enter a number."        Input x     End While
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Chapter 4 Solutions

A Guide to SQL

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