如何将数字格式化显示并且依然返回数值类型？

DB宝 2018-12-20

401

♣题目部分如何将数字格式化显示并且依然返回数值类型？

     
♣答案部分

可以使用CAST函数，示例如下所示：
SYS@PROD1> SELECT CAST(1234.4 AS NUMBER(10, 2)) AS A,
  2         CAST(12 AS NUMBER(10, 2)) AS B,
  3         CAST(0 AS NUMBER(10, 2)) AS C,
  4         CAST('1234.4' AS NUMBER(10, 2)) AS A1,
  5         CAST('12' AS NUMBER(10, 2)) AS B1,
  6         CAST('0' AS NUMBER(10, 2)) AS C1
  7    FROM DUAL;
 
           A            B            C           A1           B1           C1
------------ ------------ ------------ ------------ ------------ ------------
    1234.40        12.00         0.00      1234.40        12.00         0.00

本文选自《Oracle程序员面试笔试宝典》，作者：李华荣。