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SQL Cheat Sheet — Query Syntax Reference

The SQL statements and clauses you reach for most, with a one-line explanation of each.

Put it into practice with the matching tool.

Selecting data

SELECT * FROM users;All columns from a table

SELECT id, name FROM users;Specific columns

SELECT DISTINCT country FROM users;Unique values only

SELECT name AS full_name FROM users;Rename a column in the result

LIMIT 10Return at most 10 rows

ORDER BY created_at DESCSort results (DESC = newest first)

WHERE age > 18Basic comparison

WHERE name LIKE 'A%'Pattern match — starts with A

WHERE id IN (1, 2, 3)Match any value in a list

WHERE age BETWEEN 18 AND 30Inclusive range

WHERE email IS NULLTest for NULL (never use = NULL)

WHERE a = 1 AND b = 2Combine conditions (also OR, NOT)

INNER JOIN orders ON orders.user_id = users.idOnly rows matching in both tables

LEFT JOIN orders ON ...All left rows, plus matches (NULL where none)

RIGHT JOIN orders ON ...All right rows, plus matches

FULL OUTER JOIN orders ON ...All rows from both sides

CROSS JOIN sizesEvery combination of both tables

COUNT(*)Number of rows

SUM(amount) / AVG(amount)Total / average of a column

MIN(x) / MAX(x)Smallest / largest value

GROUP BY countryCollapse rows into groups

HAVING COUNT(*) > 3Filter groups (WHERE filters rows)

INSERT INTO users (name) VALUES ('Ada');Add a row

UPDATE users SET name = 'Ada' WHERE id = 1;Change existing rows

DELETE FROM users WHERE id = 1;Remove rows (always use WHERE)

TRUNCATE TABLE users;Delete every row, fast and unlogged

CREATE TABLE users (id INT PRIMARY KEY, name TEXT);Create a table

ALTER TABLE users ADD COLUMN email TEXT;Add a column

DROP TABLE users;Delete a table entirely

CREATE INDEX idx_name ON users(name);Speed up lookups on a column