Question

我正在尝试创建一个使用TIMESTAMP输入的oracle函数，计算该时间戳与今天之间的天数，并返回该数字。我没有正确构建它，也不知道如何解决：

create or replace FUNCTION "DAYSSINCEOPENDATE" (OPENDATE IN TIMESTAMP) 
   RETURN NUMBER
   AS
   retval  NUMBER;

        BEGIN
           SELECT (SYSDATE - CAST(OPENDATE AS DATE) FROM DUAL)) into retval;
           return retval;
        END;

感谢您的帮助。谢谢！

Answer 1

正如@Aleksej在评论中所说，the order of your clauses is incorrect；您需要

SELECT SYSDATE - CAST(OPENDATE AS DATE) into retval FROM DUAL;

所以：

create or replace FUNCTION "DAYSSINCEOPENDATE" (OPENDATE IN TIMESTAMP) 
   RETURN NUMBER
   AS
   retval  NUMBER;

        BEGIN
           SELECT SYSDATE - CAST(OPENDATE AS DATE) into retval FROM DUAL;
           return retval;
        END;
/

select DAYSSINCEOPENDATE(timestamp '2018-01-01 12:13:14.5') from dual;

DAYSSINCEOPENDATE(TIMESTAMP'2018-01-0112:13:14.5')
--------------------------------------------------
                                        204.773368

尽管实际上，您实际上不需要retval变量或针对dual的查询；您可以将其简化为

create or replace FUNCTION "DAYSSINCEOPENDATE" (OPENDATE IN TIMESTAMP) 
RETURN NUMBER
AS
BEGIN
   return SYSDATE - CAST(OPENDATE AS DATE);
END;
/

select DAYSSINCEOPENDATE(timestamp '2018-01-01 12:13:14.5') from dual;

DAYSSINCEOPENDATE(TIMESTAMP'2018-01-0112:13:14.5')
--------------------------------------------------
                                        204.773368

如何形成oracle函数-TIMESTAMP输入-日期数学-数字返回

1 个答案: