oracle 分析函数之ratio_to_report

mukeliang728

ratio_to_report函数是某个值占总值的百分比。
 
建表：
create table SMALL_CUSTOMERS(CUSTOMER_ID NUMBER,SUM_ORDERS  NUMBER);     insert into SMALL_CUSTOMERS (CUSTOMER_ID, SUM_ORDERS) values (1000, 10);     insert into SMALL_CUSTOMERS (CUSTOMER_ID, SUM_ORDERS) values (1000, 20);     insert into SMALL_CUSTOMERS (CUSTOMER_ID, SUM_ORDERS) values (1000, 30);     insert into SMALL_CUSTOMERS (CUSTOMER_ID, SUM_ORDERS) values (800, 5);     insert into SMALL_CUSTOMERS (CUSTOMER_ID, SUM_ORDERS) values (800, 10);     insert into SMALL_CUSTOMERS (CUSTOMER_ID, SUM_ORDERS) values (800, 1);  
具体用法：
select customer_id,       sum_orders,       sum(sum_orders) over(partition by customer_id) totalOrder,       round(ratio_to_report(sum_orders) over(partition by customer_id), 5) rowNumber  from small_customers t;