Mysql 执行和顺序 朱雀 2022-09-11 03:27 163阅读 0赞 # 一 手写顺序 # SELECT DISTINCT < select_list> FROM < left_table > < join_type > JOIN < right_table > ON < join_condition > WHERE < where_condition > GROUP BY < group_by_list > HAVING <having_condition > ORDER BY <order_by_condition > LIMIT < limit_number > # 二 机读顺序 # 随着 Mysql 版本的更新换代,其优化器也在不断的升级,优化器会分析不同执行顺序产生的性能消耗不同而动态调整执行顺序。 下面是经常出现的查询顺序。 1 FROM <left_table> 2 ON <join_condition> 3 <join_type> JOIN <right_table> 4 WHERE <where_condition> 5 GROUP BY <group_by_list> 6 HAVING <having_condition> 7 SELECT 8 DISTINCT <select_list> 9 ORDER BY <order_by_condition> 10 LIMIT <limit_number> # 三 机读顺序鱼骨头分析 # ![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBAY2hlbmdxaXVtaW5n_size_20_color_FFFFFF_t_70_g_se_x_16][] [watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBAY2hlbmdxaXVtaW5n_size_20_color_FFFFFF_t_70_g_se_x_16]: /images/20220828/7ca50f05c7cb4d38a6bf426df66a784c.png
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