SIGN FAQS

1. What does the Oracle SIGN function do?

The SIGN function in Oracle SQL returns the sign of a given number:

• 1 if the number is positive.
• -1 if the number is negative.
• 0 if the number is zero.

2. What is the syntax for the SIGN function in Oracle?

The syntax is:

SIGN(number)

• number: The numeric value or expression whose sign you want to evaluate.

3. What data types can be used with the SIGN function?

The SIGN function works with any numeric data type such as:

• INTEGER
• DECIMAL
• FLOAT
• NUMBER

It cannot be used with non-numeric data types (e.g., strings, dates, booleans).

4. Can the SIGN function return a non-integer value?

No, the SIGN function always returns an INTEGER value:

• 1 for positive numbers,
• -1 for negative numbers,
• 0 for zero.

5. How is the SIGN function different from the ABS function?

• SIGN returns the sign of a number: 1 for positive, -1 for negative, and 0 for zero.
• ABS returns the absolute (positive) value of a number, i.e., it always returns a non-negative number.

For example:

SELECT SIGN(-25), ABS(-25) FROM dual;

• SIGN(-25) → -1
• ABS(-25) → 25

6. Can the SIGN function be used in conditional logic?

Yes, the SIGN function is often used in CASE statements, WHERE clauses, or for conditional logic to handle positive and negative values. For example:

SELECT employee_name, salary,

       CASE

           WHEN SIGN(salary) = 1 THEN 'Positive'

           WHEN SIGN(salary) = -1 THEN 'Negative'

           ELSE 'Zero'

       END AS salary_status

FROM employees;

7. Can I use the SIGN function in aggregation queries?

Yes, you can use the SIGN function in aggregation queries to analyze values based on their sign. For example:

SELECT COUNT(*) AS negative_transactions

FROM transactions

WHERE SIGN(amount) = -1;

This query counts the number of negative transactions.

8. How can the SIGN function help in financial calculations?

The SIGN function can help determine if values represent gains or losses, such as:

• Profit (positive sign) vs Loss (negative sign).
• Identifying transactions that are above or below a certain threshold.

For example:

SELECT transaction_id, amount,

       CASE

           WHEN SIGN(amount) = 1 THEN 'Profit'

           WHEN SIGN(amount) = -1 THEN 'Loss'

           ELSE 'Neutral'

       END AS transaction_status

FROM financial_transactions;

9. Does the SIGN function handle NULL values?

The SIGN function does not handle NULL values directly. If the number passed is NULL, the function will return NULL.

For example:

SELECT SIGN(NULL) FROM dual; -- Returns NULL

10. Can I use SIGN for sorting values?

Yes, the SIGN function can be used to sort values based on whether they are positive, negative, or zero. For example:

SELECT transaction_id, amount

FROM transactions

ORDER BY SIGN(amount);  -- Sorting transactions by their sign

11. Can the SIGN function be used with complex expressions?

Yes, the SIGN function can be used with complex expressions. For example:

SELECT product_name, price, SIGN(price - target_price) AS price_comparison

FROM products;

This can help identify if the price is above, below, or equal to the target price.