读书笔记----WIDTH_BUCKET用法

 

SELECT customer_id, cust_last_name, credit_limit, 
   WIDTH_BUCKET(credit_limit, 100, 5000, 10) "Credit Group"
   FROM customers WHERE nls_territory = 'SWITZERLAND'
   ORDER BY "Credit Group";

结果：

CUSTOMER_ID CUST_LAST_NAME       CREDIT_LIMIT Credit Group

----------- -------------------- ------------ ------------

        825 Dreyfuss                      500            1

        826 Barkin                        500            1

        853 Palin                         400            1

        827 Siegel                        500            1

        843 Oates                         700            2

        844 Julius                        700            2

        835 Eastwood                     1200            3

        840 Elliott                      1400            3

        842 Stern                        1400            3

        841 Boyer                        1400            3

        837 Stanton                      1200            3

        836 Berenger                     1200            3

        848 Olmos                        1800            4

        849 Kaurusmdki                   1800            4

        851 Brown                        2300            5

        850 Finney                       2300            5

        834 Idle                         3500            7

        847 Streep                       5000           11

语法：width_bucket(exp,min_num,max_num,times);

例子解释：credit_limit：要展现的字段

 100：最小范围

 5000：最大范围

 10：在最小范围与最大范围之间分10个等级

如果超过最大范围5000 Credit Group = 10+1（超过一个等级，在本例中就是490），n 个等级以此类推。