有些小伙伴,在日常开发中总会遇到一些明明感觉写的没问题,但是执行之后结果却不是自己想要的,一般都是没有理解sql语句的执行顺序:
- FROM <left_table>
- ON <join_condition>
- <join_type> JOIN <right_table>
- WHERE <where_condition>
- GROUP BY <group_by_list>
- HAVING <having_condition>
- SELECT
- DISTINCT <select_list>
- ORDER BY <order_by_condition>
- LIMIT <limit_number>