2016-04-29 26 views
-1
SELECT DISTINCT director.lastname, director.firstname 
FROM director LEFT JOIN movdir ON director.dirnum = movdir.dirnum 

这就是我现在的情况,但我必须看一个movdir表,看看dirnum(director number)只显示一次。如果是这样,我必须去director表,并通过查看dirnum看到他们的名字是什么,并查看谁的名字是附加到该号码。董事名单

回答

2

你可以使用GROUP BYHAVING -clause:

SELECT director.lastname, director.firstname 
FROM director 
INNER JOIN movdir ON director.dirnum = movdir.dirnum 
GROUP BY director.lastname, director.firstname 
HAVING COUNT(*) = 1 
+0

一览表中有不止一个导演的电影。包括电影发行年份和电影标题。按字母顺序排序输出。 SELECT director.lastname,director.firstname FROM导演INNER JOIN movdir ON director.dirnum = movdir.dirnum GROUP BY director.lastname,director.firstname HAVING(((COUNT(*))> 1)); – Julian