Explain with example If-Then-Elsif statement
Answers
Answer:
The IF-THEN-ELSIF statement allows you to choose between several alternatives. An IF-THEN statement can be followed by an optional ELSIF...ELSE statement. The ELSIF clause lets you add additional conditions.
When using IF-THEN-ELSIF statements there are a few points to keep in mind.
It's ELSIF, not ELSEIF.
An IF-THEN statement can have zero or one ELSE's and it must come after any ELSIF's.
An IF-THEN statement can have zero to many ELSIF's and they must come before the ELSE.
Once an ELSIF succeeds, none of the remaining ELSIF's or ELSE's will be tested.
Syntax
The syntax of an IF-THEN-ELSIF Statement in PL/SQL programming language is −
IF(boolean_expression 1)THEN
S1; -- Executes when the boolean expression 1 is true
ELSIF( boolean_expression 2) THEN
S2; -- Executes when the boolean expression 2 is true
ELSIF( boolean_expression 3) THEN
S3; -- Executes when the boolean expression 3 is true
ELSE
S4; -- executes when the none of the above condition is true
END IF;
Example
DECLARE
a number(3) := 100;
BEGIN
IF ( a = 10 ) THEN
dbms_output.put_line('Value of a is 10' );
ELSIF ( a = 20 ) THEN
dbms_output.put_line('Value of a is 20' );
ELSIF ( a = 30 ) THEN
dbms_output.put_line('Value of a is 30' );
ELSE
dbms_output.put_line('None of the values is matching');
END IF;
dbms_output.put_line('Exact value of a is: '|| a );
END;
/
When the above code is executed at the SQL prompt, it produces the following result −
None of the values is matching
Exact value of a is: 100