mysql 语句的书写顺序和执行顺序

书写顺序

1. SELECT DISTINCT
2. FROM
3. JOIN ON
4. WHERE
5. GROUP BY
6. HAVING
7. ORDER BY
8. LIMIT

执行顺序

1. FROM
2. ON
3. JOIN
4. WHERE
5. GROUP BY
6. HAVING
7. SELECT
8. DISTINCT
9. ORDER BY
10. LIMIT