PL/SQL IF-THEN-ELSE statement

PL/SQL IF-THEN-ELSE statement

'if- then' is a keyword in PLSQL language .Which is used to execute one block of statements between 2 blocks
Syntax:

IF condition THEN 
   S1;  
ELSE  
   S2; 
END IF;

In the above syntax 'if' condition is true the statements of 'if' block is execute.'if' the condition is false the statements of 'else' block is execute

Example #1

DECLARE 
   a number(2) := 10; 
BEGIN 
   IF( a < 20 ) THEN 
      
      dbms_output.put_line('a is less than 20' ); 
   else
       dbms_output.put_line('a is not less than 20' ); 
   END IF; 
   
END; 
/

Example #2

DECLARE 
   c_id customers.id%type := 1; 
   c_sal  customers.salary%type; 
BEGIN 
   SELECT  salary  
   INTO  c_sal 
   FROM customers 
   WHERE id = c_id; 
   IF (c_sal <= 2000) THEN 
      UPDATE customers  
      SET salary =  salary + 1000 
         WHERE id = c_id; 
      dbms_output.put_line ('Salary 1000 updated'); 
   else
        UPDATE customers  
      SET salary =  salary + 2000 
         WHERE id = c_id; 
      dbms_output.put_line ('Salary 2000 updated'); 
   END IF; 
END; 
/