String Functions

SQL has built-in functions for working with text.

Common string functions:

• UPPER(text) - converts to uppercase
• LOWER(text) - converts to lowercase
• LENGTH(text) - returns character count
• SUBSTR(text, start, length) - extracts part of a string
• TRIM(text) - removes leading/trailing spaces

Concatenation in SQLite uses ||:

SELECT first_name || ' ' || last_name AS full_name
FROM employees;

Example:

SELECT UPPER(first_name) || ' ' || UPPER(last_name) AS full_name
FROM employees;

String functions are essential for cleaning and formatting data.