小编Rat*_*ake的帖子

我正在学习Oracle SQL,现在我仍然坚持加入章节.我无法理解Join和Natural Join之间的区别

SELECT         employee_id, job_id, department_id,
               e.last_name, e.hire_date, j.end_date
FROM           employees e
NATURAL JOIN   job_history j;

176 SA_REP 80 Taylor 24/03/2006 31/12/2006

SELECT         e.employee_id, e.job_id, e.department_id,
               e.last_name, e.hire_date, j.end_date
FROM           employees e
JOIN           job_history j
ON             (e.department_id = j.department_id)
ORDER BY        employee_id, last_name;

172 SA_REP  80  Bates   24/03/2007  31/12/2006
173 SA_REP  80  Kumar   21/04/2008  31/12/2007
173 SA_REP  80  Kumar   21/04/2008  31/12/2006
174 SA_REP  80  Abel    11/05/2004  31/12/2007
174 SA_REP  80  Abel    11/05/2004  31/12/2006
175 SA_REP  80  Hutton  19/03/2005  31/12/2007 …