SQL Quick Reference

Quick SQL reference guide.

Basic Queries

SELECT * FROM table;
SELECT col1, col2 FROM table WHERE condition;
INSERT INTO table VALUES (val1, val2);
UPDATE table SET col = val WHERE condition;
DELETE FROM table WHERE condition;

Joins

-- INNER JOIN
SELECT * FROM t1 JOIN t2 ON t1.id = t2.id;

-- LEFT JOIN
SELECT * FROM t1 LEFT JOIN t2 ON t1.id = t2.id;

Aggregations

SELECT col, COUNT(*), AVG(num) 
FROM table 
GROUP BY col 
HAVING COUNT(*) > 5;

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