我有一个表格,其中有一个以格式YYYYMM'||-||'YYYYMM
(例如:)存储的期间列201111-201203
。我需要一个 SQL 查询来生成逐行数据,每行以格式表示月份YYYYMM
。
输入
201111-201203
输出
201111
201112
201201
201202
201203
分析这段代码:
select
id, to_char(add_months(to_date(substr(interv,1,6),'yyyymm'), i),'yyyymm')
from
(Select level-1 as i from dual connect by level <= 50)
join
(
select 1 as id,'201111-201203' as interv from dual
union all
select 2, '201201-201301' from dual
)
on add_months(to_date(substr(interv,1,6),'yyyymm'), i) <=
to_date(substr(interv,-6),'yyyymm')
order by 1,2;
忘记连接和 PL/SQL:
-- List of months between dates --
SELECT to_char( add_months( start_date, LEVEL-1 ), 'YYYYMM' ) list_of_months
FROM
(
SELECT to_date('201111', 'YYYYMM') start_date,
to_date('201203', 'YYYYMM') end_date
FROM dual
)
CONNECT BY LEVEL <= MONTHS_BETWEEN(Trunc(end_date,'MM'), Trunc(start_date,'MM'))+1
/
LIST_OF_MONTHS
--------------
201111
201112
201201
201202
201203
使用这个片段来开发你的代码,你可以创建一个函数或一个过程来获得你想要的输出
declare
v_from_date date;
v_to_date date;
v_time varchar2(20);
begin
v_time := '201111-201203';
v_from_date := to_date(substr(v_time, 0, 6), 'YYYYMM');
v_to_date := to_date(substr(v_time, 8, 6), 'YYYYMM');
while v_from_date <= v_to_date loop
dbms_output.put_line(v_from_date);
v_from_date := ADD_MONTHS(v_from_date, 1);
end loop;
end;