function - PL/SQL 函数是否存在？

Question

我正在尝试创建一个名为add_extra.

CREATE OR REPLACE FUNCTION add_extra(p_price NUMBER)
RETURN NUMBER
IS
BEGIN
  RETURN(9000);
END add_extra;

但是，当我运行脚本时，它会说：

Error starting at line 1 in command:
CREATE OR REPLACE FUNCTION add_extra(p_price NUMBER)
RETURN NUMBER
IS
BEGIN
  RETURN(9000);
END add_extra;
Error report:
ORA-00955: name is already used by an existing object
00955. 00000 -  "name is already used by an existing object"
*Cause:    
*Action:

当我尝试时：DROP FUNCTION add_extra;它告诉我：

Error starting at line 1 in command:
DROP FUNCTION add_extra
Error report:
SQL Error: ORA-04043: object ADD_EXTRA does not exist
04043. 00000 -  "object %s does not exist"
*Cause:    An object name was specified that was not recognized by the system.
               There are several possible causes:
           - An invalid name for a table, view, sequence, procedure, function,
           package, or package body was entered. Since the system could not
           recognize the invalid name, it responded with the message that the
           named object does not exist.
           - An attempt was made to rename an index or a cluster, or some
           other object that cannot be renamed.
*Action:   Check the spelling of the named object and rerun the code. (Valid
           names of tables, views, functions, etc. can be listed by querying
           the data dictionary.)

它存在还是不存在？我究竟做错了什么？

Answer 1

CREATE OR REPLACE FUNCTION add_extra(p_price IN NUMBER)

__IN__您的查询中缺少关键字。

Answer 2

我几乎可以肯定它是一个FUNCTION，但它是一个PROCEDURE！所以，DROP PROCEDURE ADD_EXTRA;奏效了。