Reverse a number in PL/SQL

Reversing a number in PL/SQL involves converting the number to a string, reversing the string, and then converting it back to a number. Here's a simple PL/SQL block to reverse a given number:

DECLARE
    original_num NUMBER := 12345;
    reversed_num NUMBER;
    reversed_str VARCHAR2(100);
BEGIN
    -- Convert number to string
    reversed_str := TO_CHAR(original_num);

    -- Reverse the string
    FOR i IN REVERSE 1..LENGTH(reversed_str) LOOP
        reversed_str := SUBSTR(reversed_str, i, 1) || reversed_str;
    END LOOP;

    -- Convert the string back to a number after halving its length (since we've appended to it)
    reversed_str := SUBSTR(reversed_str, 1, LENGTH(reversed_str)/2);
    reversed_num := TO_NUMBER(reversed_str);

    DBMS_OUTPUT.PUT_LINE('Original Number: ' || original_num);
    DBMS_OUTPUT.PUT_LINE('Reversed Number: ' || reversed_num);
END;
/

The above PL/SQL block initializes a number (original_num), then reverses it, and finally prints out the original and reversed numbers. Adjust the original_num value as needed.

This method uses string manipulation functions to achieve the reversal. If performance is a concern for very large numbers or datasets, more optimized methods could be developed.

PL/SQL program to reverse a number:

Write a PL/SQL program to reverse the digits of a number.

DECLARE
    num NUMBER := 12345;
    reversed_num NUMBER := 0;
BEGIN
    WHILE num > 0 LOOP
        reversed_num := reversed_num * 10 + MOD(num, 10);
        num := TRUNC(num / 10);
    END LOOP;
    DBMS_OUTPUT.PUT_LINE('Reversed Number: ' || reversed_num);
END;
/

Reverse digits of a number in PL/SQL:

Reverse the digits of a number using PL/SQL.

DECLARE
    num NUMBER := 6789;
    reversed_num NUMBER := TO_NUMBER(REVERSE(TO_CHAR(num)));
BEGIN
    DBMS_OUTPUT.PUT_LINE('Reversed Number: ' || reversed_num);
END;
/

How to write a PL/SQL function to reverse a number:

Create a PL/SQL function to reverse a number.

CREATE OR REPLACE FUNCTION reverse_number(p_num NUMBER) RETURN NUMBER IS
    v_reversed_num NUMBER := TO_NUMBER(REVERSE(TO_CHAR(p_num)));
BEGIN
    RETURN v_reversed_num;
END reverse_number;
/

Reverse a number using a loop in PL/SQL:

Use a loop to reverse a number in PL/SQL.

DECLARE
    num NUMBER := 9876;
    reversed_num NUMBER := 0;
BEGIN
    FOR i IN 1..LENGTH(TO_CHAR(num)) LOOP
        reversed_num := reversed_num * 10 + SUBSTR(TO_CHAR(num), i, 1);
    END LOOP;
    DBMS_OUTPUT.PUT_LINE('Reversed Number: ' || reversed_num);
END;
/

PL/SQL procedure to reverse an integer:

Create a PL/SQL procedure to reverse an integer.

CREATE OR REPLACE PROCEDURE reverse_integer(p_num IN OUT NUMBER) IS
    v_reversed_num NUMBER := 0;
BEGIN
    WHILE p_num > 0 LOOP
        v_reversed_num := v_reversed_num * 10 + MOD(p_num, 10);
        p_num := TRUNC(p_num / 10);
    END LOOP;
    p_num := v_reversed_num;
END reverse_integer;
/

PL/SQL code for reversing a numeric value:

Write PL/SQL code to reverse a numeric value.

DECLARE
    num NUMBER := 54321;
    reversed_num NUMBER := TO_NUMBER(REVERSE(TO_CHAR(num)));
BEGIN
    DBMS_OUTPUT.PUT_LINE('Reversed Number: ' || reversed_num);
END;
/

Oracle PL/SQL reverse number logic:

Implement the logic to reverse a number in Oracle PL/SQL.

DECLARE
    num NUMBER := 45678;
    reversed_num NUMBER := 0;
BEGIN
    WHILE num > 0 LOOP
        reversed_num := reversed_num * 10 + MOD(num, 10);
        num := TRUNC(num / 10);
    END LOOP;
    DBMS_OUTPUT.PUT_LINE('Reversed Number: ' || reversed_num);
END;
/

Reverse order of digits in a PL/SQL program:

Reverse the order of digits in a PL/SQL program.

DECLARE
    num NUMBER := 987654;
    reversed_num NUMBER := TO_NUMBER(REGEXP_REPLACE(TO_CHAR(num), '(\d)(\d)', '\2\1'));
BEGIN
    DBMS_OUTPUT.PUT_LINE('Reversed Number: ' || reversed_num);
END;
/

PL/SQL function for reversing digits:

Create a PL/SQL function to reverse the digits of a number.

CREATE OR REPLACE FUNCTION reverse_digits(p_num NUMBER) RETURN NUMBER IS
    v_reversed_num NUMBER := TO_NUMBER(REGEXP_REPLACE(TO_CHAR(p_num), '(\d)(\d)', '\2\1'));
BEGIN
    RETURN v_reversed_num;
END reverse_digits;
/

Using REVERSE function in PL/SQL:

Utilize the REVERSE function to reverse a number in PL/SQL.

DECLARE
    num NUMBER := 123456;
    reversed_num NUMBER := TO_NUMBER(REVERSE(TO_CHAR(num)));
BEGIN
    DBMS_OUTPUT.PUT_LINE('Reversed Number: ' || reversed_num);
END;
/

Reverse a number without using additional variables in PL/SQL:

Reverse a number without using additional variables in PL/SQL.

DECLARE
    num NUMBER := 876543;
BEGIN
    DBMS_OUTPUT.PUT_LINE('Reversed Number: ' || TO_NUMBER(REGEXP_REPLACE(TO_CHAR(num), '(\d)(\d)', '\2\1')));
END;
/

PL/SQL program to reverse a decimal number:

Write a PL/SQL program to reverse a decimal number.

DECLARE
    num NUMBER := 123.45;
    integer_part NUMBER;
    decimal_part NUMBER;
BEGIN
    integer_part := TO_NUMBER(REVERSE(TO_CHAR(TRUNC(num))));
    decimal_part := TO_NUMBER(REVERSE(TO_CHAR(num - TRUNC(num))));
    DBMS_OUTPUT.PUT_LINE('Reversed Number: ' || TO_NUMBER(integer_part || '.' || decimal_part));
END;
/

Reverse a number using recursion in PL/SQL:

Reverse a number using recursion in PL/SQL.

DECLARE
    FUNCTION reverse_number(p_num NUMBER) RETURN NUMBER IS
    BEGIN
        IF p_num < 10 THEN
            RETURN p_num;
        ELSE
            RETURN MOD(p_num, 10) * POWER(10, FLOOR(LOG(10, p_num))) + reverse_number(TRUNC(p_num / 10));
        END IF;
    END reverse_number;

    num NUMBER := 987654;
    reversed_num NUMBER := reverse_number(num);
BEGIN
    DBMS_OUTPUT.PUT_LINE('Reversed Number: ' || reversed_num);
END;
/

PL/SQL query to reverse a numeric string:
- Use a PL/SQL query to reverse a numeric string.
```
SELECT TO_NUMBER(REVERSE(TO_CHAR(12345))) AS reversed_number
FROM dual;
```

Handling negative numbers when reversing in PL/SQL:

Handle negative numbers when reversing in PL/SQL.

DECLARE
    num NUMBER := -98765;
    sign NUMBER := CASE WHEN num < 0 THEN -1 ELSE 1 END;
    reversed_num NUMBER := TO_NUMBER(REVERSE(TO_CHAR(ABS(num)))) * sign;
BEGIN
    DBMS_OUTPUT.PUT_LINE('Reversed Number: ' || reversed_num);
END;
/