_学习笔记

<br />今天碰到的问题：<br /> <br /> nested exception is java.sql.SQLException: ORA-00918: column ambiguously defined<br /> <br />查到如下资料：<br /> <br />出错原因：<br />SELECT 1 AS cc ,2 AS cc FROM dual;这个语句是没错的。<br />而下面这个就有问题了：<br />SELECT * FROM (    SELECT 1 AS cc ,2 A