目录
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1.带空值的排列
2.Top/Bottom N查询
3.First/Last排名查询
4.按层次查询
一、带空值的排列：
在前面《Oracle开发专题之：分析函数2(Rank、Dense_rank、row_number)》一文中，我们已经知道了如何为一批记录进行全排列、分组排列。假如被排列的数据中含有空值呢？
SQL>?select?region_id,?customer_id,??2?????????sum(customer_sales)?cust_sales,??3?????????sum(sum(customer_sales))?over(partition?by?region_id)?ran_total,??4?????????rank()?over(partition?by?region_id??5??????????????????order?by?sum(customer_sales)?desc)?rank??6????from?user_order??7???group?by?region_id,?customer_id;