Mastering SQL String Functions

String functions in SQL are used to manipulate and process string values.

1. UPPER() and LOWER() Functions

SELECT 
    UPPER('hello') AS UpperCase, 
    LOWER('WORLD') AS LowerCase;

Output

2. LEN() Function

SELECT LEN('SQL Functions') AS StringLength;

Output. 13

3. LEFT() and RIGHT() Functions

SELECT 
    LEFT('Database', 4) AS LeftPart, 
    RIGHT('Database', 4) AS RightPart;

Output

4. SUBSTRING() Function

SELECT SUBSTRING('SQL Tutorial', 5, 8) AS SubstringResult;

Output. Tutorial

5. REPLACE() Function

SELECT REPLACE('Hello SQL', 'SQL', 'World') AS ReplacedString;

Output. Hello World

6. CONCAT() Function

SELECT CONCAT('Hello', ' ', 'SQL') AS ConcatenatedString;

Output. Hello SQL

7. LTRIM() and RTRIM() Functions

SELECT LTRIM(' SQL') AS LeftTrimmed, RTRIM('SQL ') AS RightTrimmed;

Output

8. CHARINDEX() Function

SELECT CHARINDEX('SQL', 'Learn SQL Programming') AS Position;

Output. 7 (Position of 'SQL' in the string)

9. REVERSE() Function

SELECT REVERSE('SQL') AS ReversedString;

Output. LQS

10. FORMAT() Function

SELECT FORMAT(GETDATE(), 'yyyy-MM-dd') AS FormattedDate;

Output. 2024-03-19 (Example output)

Advantages of String Functions

• Helps in text manipulation and transformation.
• Improves data formatting and presentation.
• Enhances query efficiency and readability.

String functions play a crucial role in SQL queries for processing textual data.