Part 19: Advanced Pattern Matching: ILIKE & Regular Expressions

Standard LIKE is case-sensitive in PostgreSQL and SQLite.

1. PostgreSQL ILIKE (Case-Insensitive)

SELECT * FROM users WHERE username ILIKE 'alex%';

2. Regular Expression Matching

In PostgreSQL: - ~: Matches regex (case-sensitive). - ~*: Matches regex (case-insensitive).

-- Validating email format via regex:
SELECT email FROM users WHERE email ~* '^[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,}$';

Key Takeaways

• Use ILIKE in PostgreSQL for fast case-insensitive pattern matching.
• Use regex operators (~* or REGEXP) for complex string validation.

In Part 20, we will explore Handling NULL Values: IS NULL & Three-Valued Logic!