Oracle TO_CHAR()函数出错

Question

为什么以下查询的第7行出现以下错误？

Error: ORA-01861: literal does not match format string

Query:

01: SELECT hour
02: FROM (WITH all_hours AS
03:             (SELECT TO_DATE ('2000-01-01', 'yyyy-mm-dd') 
04:                      + NUMTODSINTERVAL (LEVEL - 1, 'hour') hour
05:              FROM DUAL
06:              CONNECT BY LEVEL <= 1000000)
07:      SELECT TO_CHAR (h.hour, 'yyyy-mm-dd hh:mi am') hour
08:      FROM all_hours h
09:      GROUP BY h.hour)
10: WHERE hour BETWEEN TO_DATE ('2009-11-10 01:00 am', 'yyyy-mm-dd hh:mi am')
11:                AND TO_DATE ('2009-11-10 01:00 am', 'yyyy-mm-dd hh:mi am')

Answer 1

好吧,它不在第7行.问题是某个级别的"小时"转换为字符串(to_char),但在此之后与日期进行比较,并且隐式转换始终不起作用.更正的查询:

SELECT hour
FROM (WITH all_hours AS
            (
            SELECT TO_DATE ('2000-01-01', 'yyyy-mm-dd') 
                     + NUMTODSINTERVAL (LEVEL - 1, 'hour') hour
             FROM DUAL
             CONNECT BY LEVEL <= 1000000
             )
     SELECT TO_CHAR (h.hour, 'yyyy-mm-dd hh:mi am') hour, h.hour as hourdate
     FROM all_hours h
     GROUP BY h.hour)
WHERE hourdate BETWEEN TO_DATE ('2009-11-10 01:00 am', 'yyyy-mm-dd hh:mi am')
               AND TO_DATE ('2009-11-10 01:00 am', 'yyyy-mm-dd hh:mi am')