SELECT *
FROM (SELECT *
FROM (SELECT ROWNUM AS ROW_ID, ORDER_ID
FROM ORDERS
ORDER BY ORDER_ID DESC) A
WHERE ROW_ID < 10)
WHERE ROW_ID >= 5;--上面这样写是错误的。正确写法:
SELECT B.ORDER_ID,B.ORDER_DETAILS,B.R_ID
FROM (SELECT A.ORDER_ID,A.ORDER_DETAILS,ROWNUM AS R_ID --对排序好的结果取其rownum,再取rownum 小于给定值的记录(不能直接对rownum取大于)
FROM (SELECT ORDER_ID,ORDER_DETAILS --获取排序好的结果集
FROM ORDERS
ORDER BY ORDER_ID DESC) A
WHERE ROWNUM < 10) B
WHERE R_ID >= 5; 为什么上面是错的 ,而第二个加了别名就是正确的。
FROM (SELECT *
FROM (SELECT ROWNUM AS ROW_ID, ORDER_ID
FROM ORDERS
ORDER BY ORDER_ID DESC) A
WHERE ROW_ID < 10)
WHERE ROW_ID >= 5;--上面这样写是错误的。正确写法:
SELECT B.ORDER_ID,B.ORDER_DETAILS,B.R_ID
FROM (SELECT A.ORDER_ID,A.ORDER_DETAILS,ROWNUM AS R_ID --对排序好的结果取其rownum,再取rownum 小于给定值的记录(不能直接对rownum取大于)
FROM (SELECT ORDER_ID,ORDER_DETAILS --获取排序好的结果集
FROM ORDERS
ORDER BY ORDER_ID DESC) A
WHERE ROWNUM < 10) B
WHERE R_ID >= 5; 为什么上面是错的 ,而第二个加了别名就是正确的。
from (select t1.*,rownum rn
from (select ORDER_ID
from ORDERS
ORDER BY ORDER_ID DESC
) t1
where rownum <10
)
where rn>=5SELECT *
FROM (SELECT *
FROM (SELECT ROWNUM AS ROW_ID, ORDER_ID
FROM ORDERS
ORDER BY ORDER_ID DESC) A
WHERE ROW_ID < 10)
WHERE ROW_ID >= 5;