NTH_VALUE 取排名

FROM http://blog.csdn.net/jgmydsai/article/details/10574423

Connected to Oracle Database 11g Enterprise Edition Release 11.2.0.1.0

 SQL> SELECT NTH_VALUE(T.SNAME, 3) FROM FIRST OVER() AS 第三名,
   2         NTH_VALUE(T.SNAME, 2) FROM LAST OVER() AS 倒数第二名,
   3         T.*
   4    FROM STUDENT T
   5   ORDER BY AGE;
 第三名     倒数第二名    SNO SNAME             AGE
 ---------- ---------- ----- ---------- ----------
 KAY        CHAD           6 JING               18
 KAY        CHAD           4 MAGGIE             19
 KAY        CHAD           8 KAY                20
 KAY        CHAD           1 AARON              20
 KAY        CHAD           3 DOUG               20
 KAY        CHAD           9 GILLIAN            20
 KAY        CHAD           7 BRIAN              21
 KAY        CHAD           2 CHUCK              21
 KAY        CHAD          10 CHAD               21
 KAY        CHAD           5 STEVE              22
 10 rows selected

 SQL>

注意，看例句中的重复记录，用NTH_VALUE只能取到其中一个