limit 0,1, 从你的表中的第0个数据开始,只读取一个;
我们再看下mysql解释sql语言时的执行顺序:
(7) SELECT
(8) DISTINCT <select_list>
(1) FROM <left_table> (3) <join_type> JOIN <right_table> (2) ON <join_condition> (4) WHERE <where_condition> (5) GROUP BY <group_by_list> (6) HAVING <having_condition> (9) ORDER BY <order_by_condition> (10) LIMIT <limit_number>
在我们本文的案例sql中,执行顺序依次为form… where… select… order by… limit…