DML：SELECT INSERT UPDATE DELETE FROM WHERE SET VALUES INTO

连接：JOIN LEFT JOIN RIGHT JOIN INNER JOIN CROSS JOIN ON

条件：AND OR NOT IN BETWEEN LIKE EXISTS IS NULL

排序/分组：ORDER BY GROUP BY HAVING ASC DESC LIMIT

DDL：CREATE TABLE ALTER TABLE DROP TABLE ADD COLUMN PRIMARY KEY

函数：COUNT SUM AVG MAX MIN COALESCE IFNULL CASE WHEN