Statement that enables PL/SQL to perform actions selectively based on conditions.

Control structures Repetition statements that enable you to execute statements in a PL/SQL block repeatedly.

An expression with a TRUE or FALSE value that is used to make a decision. An expression that determines a course of action based on conditions and can be used outside a PL/SQL block in a SQL statement.

1.What is the purpose of a conditional control structure in PL/SQL?

List the three categories of control structures in PL/SQL.

1.Write a PL/SQL block to find the population of a given country in the countries table. Display a message indicating whether the population is greater than or less than 1 billion (1,000,000,000). Test your block twice using India (country_id = 91) and United Kingdom (country_id = 44). Indias population should be greater than 1 billion, while United Kingdoms should be less than 1 billion.

1.Modify the code from the previous exercise so that it handles all the following cases:

A.Population is greater than 1 billion.

B.Population is greater than 0.

C.Population is 0.

D.Population is null. (Display: No data for this country.)

Run your code using the following country ids. Confirm the indicated results.

China (country_id = 86): Population is greater than 1 billion.

United Kingdom (country_id = 44): Population is greater than 0.

Antarctica (country_id = 672): Population is 0.

Europa Island (country_id = 15): No data for this country.

DECLARE

v_country_id countries.country_name%TYPE := ; v_ind_date countries.date_of_independence%TYPE; v_natl_holiday countries.national_holiday_date%TYPE;

BEGIN

SELECT date_of_independence, national_holiday_date

INTO v_ind_date, v_natl_holiday

FROM countries

WHERE country_id = v_country_id;

IF v_ind_date IS NOT NULL THEN DBMS_OUTPUT.PUT_LINE('A');

ELSIF v_natl_holiday IS NOT NULL THEN

DBMS_OUTPUT.PUT_LINE('B');

ELSIF v_natl_holiday IS NULL AND v_ind_date IS NULL THEN

DBMS_OUTPUT.PUT_LINE('C');

END IF;

END;

What would print if the country has an independence date equaling NULL and a national holiday date equaling NULL?

What would print if the country has an independence date equaling NULL and a national holiday date containing a value?

What would print if the country has an independence date equaling a value and a national holiday date equaling NULL?