Question

可能是一个愚蠢的错误，但我自己也无法解决这个问题。当我在Oracle 11g中运行此查询时。

如果在SO中回答了这个问题，请告诉我链接。

with LAST_BUSINESS_DAY as (select DECODE(to_char(last_day(to_date('29-mar-2013')), 'D'), 
                                  , '7', to_char((last_day('29-mar-2013') - 1), 'DD-MON-YYYY')
                                  , '1', to_char((last_day('29-mar-2013') - 2), 'DD-MON-YYYY')
                                  , to_char(last_day('29-apr-2013'), 'DD-MON-YYYY')) as LAST_BD from dual),
      HOLIDAYS as (select distinct rpt_day
                     from rpt_days rpt left join
                          calendars cal on rpt.calendar_id = cal.calendar_id
                    where rpt.type = 2 
                      and cal.group = 4)
  select case when to_char(to_date(LAST_BD, 'DD-MON-YYYY'), 'D') is null
              then LAST_BD
              else DECODE(to_char(to_date(LAST_BD, 'DD-MON-YYYY') , 'D')
                          , '6', LAST_BD
                          , '2', LAST_BD
                          , LAST_BD)
         end as LAST_BD_OF_MONTH
    from LAST_BUSINESS_DAY LBD 
         inner join HOLIDAYS H on LBD.LAST_BD = H.rpt_day

我得到结果

LAST_BD_OF_MONTH
===================
29-MAR-2013

现在，当我尝试在LAST_BD日期添加一天时，会抛出错误。

with LAST_BUSINESS_DAY as (select DECODE(to_char(last_day(to_date('29-mar-2013')), 'D'), 
                                  , '7', to_char((last_day('29-mar-2013') - 1), 'DD-MON-YYYY')
                                  , '1', to_char((last_day('29-mar-2013') - 2), 'DD-MON-YYYY')
                                  , to_char(last_day('29-apr-2013'), 'DD-MON-YYYY')) as LAST_BD from dual),
      HOLIDAYS as (select distinct rpt_day
                     from rpt_days rpt left join
                          calendars cal on rpt.calendar_id = cal.calendar_id
                    where rpt.type = 2 
                      and cal.group = 4)
  select case when to_char(to_date(LAST_BD, 'DD-MON-YYYY'), 'D') is null
              then LAST_BD
              else DECODE(to_char(to_date(LAST_BD, 'DD-MON-YYYY') , 'D') -- line 35
                          , '6', LAST_BD - 1 -- CHANGED THIS
                          , '2', LAST_BD + 1 -- CHANGED THIS
                          , LAST_BD)
         end as LAST_BD_OF_MONTH
    from LAST_BUSINESS_DAY LBD 
         inner join HOLIDAYS H on LBD.LAST_BD = H.rpt_day

错误消息

ORA-00932：数据类型不一致：预期CHAR得到NUMBER   00932. 00000 - ＆＃34;不一致的数据类型：预期％s得到％s＆＃34;   *原因：
  *动作：行错误：35列：20

正如我所说，这可能是我身边的一个简单的忽视。我尝试将LAST_BD转换为date，但没有效果。

我尝试更改DECODE，如下所示

case when to_char(to_date(LAST_BD, 'DD-MON-YYYY'), 'D') is null
     then LAST_BD
     else DECODE(to_char(to_date(LAST_BD, 'DD-MON-YYYY') , 'D')
                 , '6', to_date(LAST_BD, 'DD-MON-YYYY') - 1
                 , '2', LAST_BD + 1 -- line 37
                 , LAST_BD)
end as LAST_BD_OF_MONTH

并收到此错误：

ORA-00932：不一致的数据类型：预期DATE得到NUMBER   00932. 00000 - ＆＃34;不一致的数据类型：预期％s得到％s＆＃34;   *原因：
  *动作：行错误：37列：42

所以，我将line 37更改为此，

case when to_char(to_date(LAST_BD, 'DD-MON-YYYY'), 'D') is null
     then LAST_BD
     else DECODE(to_char(to_date(LAST_BD, 'DD-MON-YYYY') , 'D')
                , '6', to_date(LAST_BD, 'DD-MON-YYYY') - 1
                , '2', to_date(LAST_BD, 'DD-MON-YYYY') + 1
                , LAST_BD)
end as LAST_BD_OF_MONTH

这次是另一条消息。

ORA-00932：不一致的数据类型：预期CHAR得到日期
  00932. 00000 - ＆＃34;不一致的数据类型：预期％s得到％s＆＃34;   *原因：
  *动作：行错误：35列：20

非常感谢任何有助于纠正此问题的帮助。

答案：

with LAST_BUSINESS_DAY as (select DECODE(to_char(last_day(to_date('29-mar-2013')), 'D'), 
                                  , '7', to_char((last_day('29-mar-2013') - 1), 'DD-MON-YYYY')
                                  , '1', to_char((last_day('29-mar-2013') - 2), 'DD-MON-YYYY')
                                  , to_char(last_day('29-apr-2013'), 'DD-MON-YYYY')) as LAST_BD from dual),
      HOLIDAYS as (select distinct rpt_day
                     from rpt_days rpt left join
                          calendars cal on rpt.calendar_id = cal.calendar_id
                    where rpt.type = 2 
                      and cal.group = 4)
  select case when to_char(to_date(LAST_BD, 'DD-MON-YYYY'), 'D') is null
              then LAST_BD
              else DECODE(to_char(to_date(LAST_BD, 'DD-MON-YYYY') , 'D')
                          , '6', to_char (to_date(LAST_BD, 'DD-MON-YYYY') - 1, 'DD-MON-YYYY')
                          , '2', to_char (to_date(LAST_BD, 'DD-MON-YYYY') + 1, 'DD-MON-YYYY')
                          , LAST_BD)
         end as LAST_BD_OF_MONTH
    from LAST_BUSINESS_DAY LBD 
         inner join HOLIDAYS H on LBD.LAST_BD = H.rpt_day

Answer 1

所以我认为是正确的，您将LAST_BD从VARCHAR2转换为DATE（由于）：

to_date(LAST_BD, 'DD-MON-YYYY')

在第二个查询中，您尝试从此1：

中减去VARCHAR2

LAST_BD - 1

这不会奏效。结果你得到错误：

ORA-00932: inconsistent datatypes: expected CHAR got NUMBER

如果将其转换为DATE，可能会有用，添加1并将其转换回VARCHAR2

with LAST_BUSINESS_DAY as (select DECODE(to_char(last_day(to_date('29-mar-2013')), 'D'), 
                                  , '7', to_char((last_day('29-mar-2013') - 1), 'DD-MON-YYYY')
                                  , '1', to_char((last_day('29-mar-2013') - 2), 'DD-MON-YYYY')
                                  , to_char(last_day('29-apr-2013'), 'DD-MON-YYYY')) as LAST_BD from dual),
      HOLIDAYS as (select distinct rpt_day
                     from rpt_days rpt left join
                          calendars cal on rpt.calendar_id = cal.calendar_id
                    where rpt.type = 2 
                      and cal.group = 4)
  select case when to_char(to_date(LAST_BD, 'DD-MON-YYYY'), 'D') is null
              then LAST_BD
              else DECODE(to_char(to_date(LAST_BD, 'DD-MON-YYYY') , 'D') -- line 35
                     , '6', to_char (to_date(LAST_BD, 'DD-MON-YYYY') - 1, 'DD-MON-YYYY') 
                     , '2', to_char (to_date(LAST_BD, 'DD-MON-YYYY') + 1, 'DD-MON-YYYY') 
                          , LAST_BD)
         end as LAST_BD_OF_MONTH
    from LAST_BUSINESS_DAY LBD 
         inner join HOLIDAYS H on LBD.LAST_BD = H.rpt_day

请注意，需要转换回VARCHAR2，因为DECODE仅允许一种类型的值。

Answer 2

问题是DECODE需要某种CHAR参数，LAST_BD + 1甚至TO_DATE(LAST_BD...分别返回NUMBER和DATE。

以下SQL小提琴演示如何解决此问题。

http://sqlfiddle.com/#!4/8ac4a3/9

以下是查询：

with LAST_BUSINESS_DAY as (select DECODE(to_char(last_day(to_date('29-mar-2013')), 'D')
                                  , '7', to_char((last_day('29-mar-2013') - 1), 'DD-MON-YYYY')
                                  , '1', to_char((last_day('29-mar-2013') - 2), 'DD-MON-YYYY')
                                  , to_char(last_day('29-apr-2013'), 'DD-MON-YYYY')) as LAST_BD from dual),
      HOLIDAYS as (select distinct reporting_day
                     from tbm_reporting_days trdy left join
                          tbm_calendars tcal on trdy.calendar_id = tcal.calendar_id
                    where trdy.type = 2 
                      and tcal.site_id = 4)
  select case when to_char(to_date(LAST_BD, 'DD-MON-YYYY'), 'D') is null
              then LAST_BD
              else DECODE(to_char(to_date(LAST_BD, 'DD-MON-YYYY') , 'D')
                          , '6', TO_CHAR(
                              (TO_DATE(LAST_BD, 'DD-MON-YYYY') - 1), 'D')
                          , '2', TO_CHAR(
                              (TO_DATE(LAST_BD, 'DD-MON-YYYY') - 1), 'D')
                          , LAST_BD)
         end as LAST_BD_OF_MONTH
    from LAST_BUSINESS_DAY LBD 
         inner join HOLIDAYS H on LBD.LAST_BD = H.reporting_day

您必须使用TO_CHAR将数字或日期转换回CHAR。

Answer 3

似乎Oracle要求 case 结构所有 then 表达式的类型与第一个然后之后的表达式类型一致。
不会执行类型转换。

ORA-00932：不一致的数据类型：预期CHAR在为日期添加1时获得NUMBER

3 个答案: