PL/SQL - Nested IF-THEN-ELSE Statements
It is always legal in PL/SQL programming to nest IF-ELSE statements, which means you can use one IF or ELSE IF statement inside another IF or ELSE IF statement(s).
IF( boolean_expression 1)THEN -- executes when the boolean expression 1 is true IF(boolean_expression 2) THEN -- executes when the boolean expression 2 is true sequence-of-statements; END IF; ELSE -- executes when the boolean expression 1 is not true else-statements; END IF;
DECLARE a number(3) := 100; b number(3) := 200; BEGIN -- check the boolean condition IF( a = 100 ) THEN -- if condition is true then check the following IF( b = 200 ) THEN -- if condition is true then print the following dbms_output.put_line('Value of a is 100 and b is 200' ); END IF; END IF; dbms_output.put_line('Exact value of a is : ' || a ); dbms_output.put_line('Exact value of b is : ' || b ); END; /
When the above code is executed at SQL prompt, it produces the following result:
Value of a is 100 and b is 200 Exact value of a is : 100 Exact value of b is : 200 PL/SQL procedure successfully completed.