oracle - WAP 在 pl/sql 中创建包含基本数学运算函数的包名称计算器

Question

收到错误

SQL> selectcalculator.add(10,10) from dual;

从对偶中选择calculator.add(10,10)

第 1 行的错误：

ORA-01747: 无效的 user.table.column、table.column 或列规范

SQL*Plus：2019 年 11 月 24 日星期日 13:58:08 发布 11.2.0.1.0 生产版

SQL> ed
Wrote file *afiedt.buf*

  1  create or replace package body calculator
  2  as
  3      function add(x number, y number) return number;
  4      function subtract(x number, y number) return number;
  5      function multiply(x number, y number) return number;
  6      function divide(x number, y number) return number;
  7* end;

SQL> /

Warning: Package Body created with compilation errors.

SQL>

SQL> get pkg_bdy_cal

  1  create or replace package body calculator
  2  as
  3     function add(x number, y number) return number
  4     is
  5     begin
  6         return (x + y);
  7     end;
  8     function subtract(x number, y number) return number
  9     is
 10     begin
 11         return (x - y);
 12     end;
 13     function multiply(x number, y number) return number
 14     is
 15     begin
 16         return (x * y);
 17     end;
 18     function divide(x number, y number) return number
 19     is
 20     begin
 21         return (x / y);
 22     end;
 23* end calculator;

SQL> /

Warning: Package Body created with compilation errors.

SQL> show error
Errors for PACKAGE BODY CALCULATOR:

LINE/COL ERROR
-------- -----------------------------------------------------------------
0/0      PL/SQL: Compilation unit analysis terminated

1/14     PLS-00304: cannot compile body of 'CALCULATOR' without its
         specification

1/14     PLS-00905: object SYSTEM.CALCULATOR is invalid