PL/SQL Program to Check Whether a Number is Prime or Not

This PL/SQL script checks whether a given number is a prime number using a simple loop and conditional logic. A must-know example for SQL developers and interview candidates.

PL/SQL Code to Check Prime Number

DECLARE
  num NUMBER := 29;
  i NUMBER := 2;
  is_prime BOOLEAN := TRUE;
BEGIN
  IF num <= 1 THEN
    is_prime := FALSE;
  ELSE
    WHILE i <= SQRT(num) LOOP
      IF MOD(num, i) = 0 THEN
        is_prime := FALSE;
        EXIT;
      END IF;
      i := i + 1;
    END LOOP;
  END IF;

  IF is_prime THEN
    DBMS_OUTPUT.PUT_LINE(num || ' is a Prime Number');
  ELSE
    DBMS_OUTPUT.PUT_LINE(num || ' is Not a Prime Number');
  END IF;
END;
    

How It Works

• Starts loop from 2 to √n
• Uses MOD(num, i) to check for divisibility
• Boolean flag is_prime determines the result

FAQs

What is the best way to check primes in PL/SQL? Use loop up to square root for optimal performance. What if the number is negative? It will be marked as not prime.

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Published by SQLQueries.in | Last updated: July 26, 2025