复制create table sales ( sales_id number,数据 cust_id number, sales_amt number, sale_category varchar2(6) /* 虚拟列名及数据类型*/ generated always as ( case when sales_amt <= 10000 then LOW when sales_amt > 10000 and sales_amt <= 100000 then MEDIUM when sales_amt > 100000 and sales_amt <= 1000000 then HIGH else ULTRA end ) virtual /*虚拟列值函数内容*/ ); 1.2.3.4.5.6.7.8.9.10.11.12.13.14.15.16.17.18.19.20.21.22.23.24.25.