PL SQL

Hi Everyone, Today's topic is conditional control(if,ifelse,case,goto,null).

PL/SQL supports the programming language features like conditional statements and iterative statements.

Its programming constructs are similar to how you use in programming languages like Java and C++.

Conditional Statements are basically used when condition occurs and we choose one statements.

IF

It allows you to either execute or skip a sequence of statements, depending on a condition.

The IF statement has the three forms:

1. IF THEN 2. IF THEN ELSE 3. IF THEN ELSIF

IF THEN :

IF condition   
THEN 
Statement:    -- It is executed when condition is true 
END IF;  

Example:

DECLARE num NUMBER := 234; 
BEGIN 
   IF num > 0 THEN 
      DBMS_OUTPUT.PUT_LINE( 'Number is Positive ' ); 
   END IF; 
END;

Output:

Statement processed.
Number is Positive 

IF THEN ELSE :

IF condition   
THEN 
Statement:    -- It is executed when condition is true 

ELSE

Statements      --statements to execute when condition is FALSE 

END IF;  

Example:

DECLARE num NUMBER := -234; 
BEGIN 
   IF num >= 0 
   THEN 
      DBMS_OUTPUT.PUT_LINE( 'Number is Positive ' ); 
   ELSE
    DBMS_OUTPUT.PUT_LINE( 'Number is Negative ' ); 

   END IF; 
END;

Output:

Statement processed.
Number is Negative 

IF THEN ELSEIF :

IF condition_1  
THEN 
Statement_1:    -- It is executed when condition_1 is true 

ELSEIF condition_2

THEN

Statement2      --statements to execute when condition_2 is TRUE 

ELSE

Statement3      --statements to execute when condition-2_is FALSE 

END IF;  

Example:

DECLARE
  e_salary NUMBER := 30000;
BEGIN
  IF e_salary > 20000 THEN
    e_salary := e_salary + 5000;
    dbms_output.put_line(' New Salary is : ' || e_salary  );  

  ELSIF e_salary <= 20000 AND e_salary > 10000 THEN 
    e_salary := e_salary + 2000;
    dbms_output.put_line(' New Salary is : ' || e_salary );  

  ELSIF e_salary <= 10000 AND e_salary > 5000 THEN 
    e_salary := e_salary + 1000 ;
   dbms_output.put_line(' New Salary is : ' || e_salary);  

  ELSE
    e_salary := e_salary + 5000;
    dbms_output.put_line(' New Salary is : ' || e_salary);  

  END IF;
END;

Output:

Statement processed.
 New Salary is : 35000

I will Upload CASE statement later. Keep Connected.

Thank you for reading.

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