我正在尝试编写一个查询，该查询将根据以下条件为我提供max date表单。Table_A
如果给定日期（输入参数）在当年的 4 月 1 日到9 月 30 日MAX(date)之间，则在 4 月 1 日之前返回。
或者
如果给定日期（输入参数）介于 10 月 1 日和次年3 月 31 日之间MAX(date)，则在 10 月 1 日之前返回。
例如 ：
尝试这个：
select max(case
when trunc(the_date) between to_date('01-apr-'||the_year, 'dd-mon-yyyy')
and to_date('30-sep-'||the_year, 'dd-mon-yyyy')
and dte < to_date('01-apr-'||the_year, 'dd-mon-yyyy')
then
dte
when trunc(the_date) between to_date('01-oct-'||the_year, 'dd-mon-yyyy')
and to_date('31-mar-'||(the_year+1), 'dd-mon-yyyy')
and dte < to_date('01-oct-'||the_year, 'dd-mon-yyyy')
then
dte
end) max_date
from table_a a
cross join (select v_inp_date the_date,
to_char(add_months(v_inp_date,-3), 'yyyy') the_year
from dual) dte;
所以你输入的日期在dte部分
v_inp_date
和
to_char(add_months(v_inp_date,-3), 'yyyy') the_year
例如一个小测试：
SQL> create table table_a(dte date);
Table created.
SQL> insert into table_a values(to_date('28-sep-2012', 'dd-mon-yyyy'));
1 row created.
SQL> insert into table_a values(to_date('29-sep-2012', 'dd-mon-yyyy'));
1 row created.
SQL> insert into table_a values(to_date('28-mar-2012', 'dd-mon-yyyy'));
1 row created.
SQL> insert into table_a values(to_date('29-mar-2012', 'dd-mon-yyyy'));
1 row created.
SQL> insert into table_a values(to_date('28-sep-2011', 'dd-mon-yyyy'));
1 row created.
SQL> insert into table_a values(to_date('27-mar-2011', 'dd-mon-yyyy'));
1 row created.
SQL> commit;
Commit complete.
SQL> var inpdate varchar2(20);
SQL> exec :inpdate := '27-dec-2012';
PL/SQL procedure successfully completed.
SQL> select max(case
2 when trunc(the_date) between to_date('01-apr-'||the_year, 'dd-mon-yyyy')
3 and to_date('30-sep-'||the_year, 'dd-mon-yyyy')
4 and dte < to_date('01-apr-'||the_year, 'dd-mon-yyyy')
5 then
6 dte
7 when trunc(the_date) between to_date('01-oct-'||the_year, 'dd-mon-yyyy')
8 and to_date('31-mar-'||(the_year+1), 'dd-mon-yyyy')
9 and dte < to_date('01-oct-'||the_year, 'dd-mon-yyyy')
10 then
11 dte
12 end) max_date
13 from table_a a
14 cross join (select to_date(:inpdate,'dd-mon-yyyy') the_date,
15 to_char(add_months(to_date(:inpdate,'dd-mon-yyyy'), -3), 'yyyy') the_year
16 from dual) dte;
MAX_DATE
---------
29-SEP-12
SQL> exec :inpdate := '17-aug-2012';
PL/SQL procedure successfully completed.
SQL> /
MAX_DATE
---------
29-MAR-12
SQL> exec :inpdate := '01-oct-2011';
PL/SQL procedure successfully completed.
SQL> /
MAX_DATE
---------
28-SEP-11
SQL> exec :inpdate := '01-apr-2011';
PL/SQL procedure successfully completed.
SQL> /
MAX_DATE
---------
27-MAR-11
SQL>
我的示例中的结束日期是 2012 年 12 月 31 日，您可以将其延长至 2013 年以上。我正在即时构建表格 - 为每一行打印 max_date。另外，我对最大日期进行硬编码。您不需要执行任何此操作，这只是示例。将 &1 和 &2 替换为不带引号的值...：
SELECT date_table --, start_date, end_date
, (CASE WHEN date_table BETWEEN To_Date('01-APR-2012') And To_Date('30-SEP-2012') Then max_apr_date
WHEN date_table BETWEEN To_Date('01-OCT-2012') And To_Date('31-DEC-2012') Then max_oct_date
END) max_date
FROM
(
SELECT *
FROM
(
SELECT TRUNC(SYSDATE,'Y')+LEVEL-1 date_table
, To_Date('&1') start_date
, To_Date('&2') end_date
, '29-MAR-2012' max_apr_date
, '29-Sep-2012' max_oct_date
FROM dual
CONNECT BY LEVEL <= (ADD_MONTHS(TRUNC(SYSDATE,'Y'),12)-TRUNC(SYSDATE,'Y') )
)
WHERE date_table BETWEEN start_date AND end_date
)
/