Chapter 3, Problem 4PE

a.

Program Plan Intro

SELECT statement:

It is used to retrieve information from the table or database. The syntax for the “SELECT” statement is given below:

Syntax:

SELECT * FROM table_Name;

CASE statement:

The CASE statement checks through the condition and returns a value when the first condition is satisfied. If none of the conditions is true, it returns the value in the ELSE clause.

Syntax:

CASE

    WHEN condition_1 THEN result_1

    WHEN condition_2 THEN result_2

    WHEN condition_N THEN result_N

    ELSE result

END;

b.

Program Plan Intro

GROUP BY Clause:

The GROUP BY clause is used to group the result of a SELECT statement done on a table where the tuple values are similar for more than one column

Syntax:

SELECT expression1, expression2, expression_n, aggregate_function (expression)FROM table_name WHERE conditions GROUP BY expression1, expression2, expression_n;

“COUNT()” function:

In SQL, the “COUNT()” function will return the total number of rows in the table with satisfying the criteria mentioned in the “WHERE” clause.

CASE statement:

The CASE statement checks through the condition and returns a value when the first condition is satisfied. If none of the conditions is true, it returns the value in the ELSE clause.

Syntax:

CASE

    WHEN condition_1 THEN result_1

    WHEN condition_2 THEN result_2

    WHEN condition_N THEN result_N

    ELSE result

END;