SQL Tutorial

Scalar Functions in SQL

Scalar functions operate on a single value and return a single value. Unlike aggregate functions, they do not work on groups of rows but on individual fields and can be used in SELECT, WHERE, and ORDER BY clauses.

🧾 Categories of Scalar Functions

• String Functions – Operate on string values
• Numeric Functions – Operate on numeric data
• Date Functions – Work with date and time values
• Conversion Functions – Convert data from one type to another

🔤 Common Scalar Functions

• UPPER() – Converts text to uppercase
• LOWER() – Converts text to lowercase
• LENGTH() – Returns the length of a string
• ROUND() – Rounds a number to a given decimal place
• NOW() – Returns the current date and time
• GETDATE() – Returns the current system timestamp (SQL Server)
• CONVERT() – Converts a value from one data type to another

📋 Syntax

SELECT SCALAR_FUNCTION(column_name)
FROM table_name
WHERE condition;
  

💡 Examples

SELECT UPPER(Name) FROM Customers;

SELECT ROUND(Price, 2) FROM Products;

SELECT NOW();

📌 Conclusion

Scalar functions are essential for performing transformations on individual data values. Whether you’re formatting strings, rounding numbers, or manipulating dates, these functions make data presentation and filtering more efficient and readable.