SQL Keywords

Keyword	Meaning	Example
SELECT	Choose which columns to return	SELECT name, age FROM patients;
FROM	Specify the table to pull data from	FROM staff
WHERE	Filter rows based on conditions	WHERE age > 60
AND / OR	Combine multiple conditions	WHERE age > 60 AND service = 'Cardiology'
IN	Match against a list of values	WHERE service IN ('Emergency', 'Surgery')
BETWEEN	Filter within a numeric or date range	WHERE age BETWEEN 18 AND 65
LIKE	Search for a pattern (wildcards)	WHERE name LIKE 'J%'
IS NULL / IS NOT NULL	Check for missing values	WHERE discharge_date IS NULL
ORDER BY	Sort results by column(s)	ORDER BY age DESC
DISTINCT	Remove duplicate rows	SELECT DISTINCT service FROM patients;
LIMIT	Restrict number of rows returned	LIMIT 10