原文：https://www.sqlite.org/lang_explain.html
症结字EXPLAIN”或语句（by the phrase）“EXPLAIN QUERY PLAN”可以放置在SQL语句之前。（关于这句话供给原文，便利后来者观看An SQL statement can be preceded by the keyword “EXPLAIN”）.如果没有EXPLAIN症结字或语句，SQL语句和平凡返回查询信息没有甚么两样（Either modification causes the SQL statement to behave as qeruy and to return informationabout how the SQL statement would have operated if the EXPLAIN keyword orphrase had been omitted.）
