4

伙计们，我需要列出上个月的所有日期，如下所示

20101201
20101202
20101203
20101204
20101205
..
..
..
..
..
..
..
..
20101231

请让我知道是否有比此查询更好的方法。

select TO_CHAR(TRUNC(SYSDATE,'MM')-1,'YYYYMMDD')-(level-1) as 
EACH_DATE from dual A connect by level 
< (TO_NUMBER(TO_CHAR(TRUNC(SYSDATE,'MM')-1,'DD'))+1)

另外请让我知道这个查询的问题，它说“缺少右括号”

SELECT /*+ PARALLEL (A,8) */ /*+ DRIVING_STATE */
   TO_CHAR(TRUNC(TRUNC(SYSDATE,'MM')-1,'MM'),'MONYYYY') "MONTH", TYPE AS "TRAFF",     COLUMN, A_COUN AS "A_COUNT",COST  FROM DATA_P B WHERE  EXISTS  
(  
  select TO_NUMBER(TO_CHAR(TRUNC(SYSDATE,'MM')-1,'YYYYMMDD')-(level-1))  EACH_DATE 
  from dual A connect by  level < TO_NUMBER(TO_CHAR(TRUNC(SYSDATE,'MM')-1,'DD')+1) 
  WHERE A.EACH_DATE = B.DATE  order by EACH_DATE ASC
 )

强调文本

4

5 回答 5

7

听起来你想要这样的东西

SQL> ed
Wrote file afiedt.buf

  1  select to_char( add_months(trunc(sysdate,'MM'),-1) + level - 1,
  2                  'YYYYMMDD' )
  3    from dual
  4  connect by level <=
  5    last_day(add_months(trunc(sysdate,'MM'),-1)) -
  6    add_months(trunc(sysdate,'MM'),-1) +
  7*   1
SQL> /

TO_CHAR(
--------
20101201
20101202
20101203
20101204
20101205
20101206
20101207
20101208
20101209
20101210
20101211
20101212
20101213
20101214
20101215
20101216
20101217
20101218
20101219
20101220
20101221
20101222
20101223
20101224
20101225
20101226
20101227
20101228
20101229
20101230
20101231

31 rows selected.
于 2011-01-10T08:51:10.147 回答
3

本月：

SELECT  TO_CHAR (TRUNC (SYSDATE, 'MM'), 'YYYYMMDD')+(LEVEL - 1) each_date
FROM    DUAL a
CONNECT BY LEVEL < (TO_NUMBER (TO_CHAR (TRUNC (SYSDATE, 'MM') - 1, 'DD'))+1)
于 2012-11-15T05:16:19.577 回答
1

一点 add_months 肯定会让它变得更好，例如

select to_char(x,'yyyymmdd') from (
  select add_months(trunc(sysdate,'MONTH'),-1)+rownum-1 x from all_objects
) where x<trunc(sysdate,'MONTH');
于 2011-01-10T08:31:39.260 回答
1

这可能更容易理解：

select TO_CHAR(d, 'YYYYMMDD')
from (
  select ADD_MONTHS(TRUNC(SYSDATE, 'MM'), -1) + (ROWNUM - 1) d
  from DUAL connect by level <= 31
)
where d < TRUNC(SYSDATE, 'MM')

但是，“按级别连接”方法是最清晰的，并且如此处所述，生成数字序列的更快方法。我认为没有办法显着改善您的查询。

于 2011-01-10T09:23:44.367 回答
0

就正确的括号而言，您试图以错误的方式连接字符串：

select TO_CHAR(TRUNC(SYSDATE,'MM')-1,'YYYYMMDD')-(level-1) as

应该管用：

select TO_CHAR(TRUNC(SYSDATE,'MM')-1,'YYYYMMDD') || '-' || To_Char(level-1) as

显然，您不希望发生串联。因此，我认为您实际上想将级别添加到TRUNC()-part

使固定：

select TO_CHAR(TRUNC(SYSDATE,'MM') - 1 + level - 1,'YYYYMMDD') as 
EACH_DATE from dual A connect by level 
< (TO_NUMBER(TO_CHAR(TRUNC(SYSDATE,'MM')-1,'DD'))+1)
于 2011-01-10T08:58:44.947 回答