In the previous lesson we learned about
OR operator and operator precedence and how to control it with parentheses:
SELECT COUNT(*) FROM users WHERE (country = 'ca' OR country = 'gb' OR country = 'au' OR country = 'us') AND signup_date BETWEEN '2018-02-01' AND '2018-02-07'
How do you like it? It often helps to ask the question “Can we do better?”. We clearly have room for improvement, as this query grew really big.
OR operator did a great job and if you need to apply filters for different columns it’s the only way to go. Since we’re...