SELECT语句的完整语法为：(7) SELECT (8) DISTINCT <select_list>(1) FROM <left_table>(3) <join_type> JOIN <r

目录一:mysql执行过程1.1:连接器1.2:缓存1.3:分析器1.4:优化器1.5:执行器二：执行的状态三:sql的执行顺序3.1：from3.2:join on3.3:where3.4:group by3.5:Having3.6:se