8

我需要生成一系列季度，给定开始日期和结束日期。我知道generate_series()，但它不适用于quarter：

SELECT * FROM generate_series('2008-01-01 00:00'::timestamp,'2009-01-01 12:00', '1 quarter');

是什么让季度如此特别？否则generate_series()适用于几乎所有东西，从微秒到千年：

select * from generate_series('2008-01-01 00:00'::timestamp,'2008-01-01 00:00:00.001', '1 microsecond');
select * from generate_series('2008-01-01 00:00'::timestamp,'2008-01-01 00:01', '1 second');
select * from generate_series('2008-01-01 00:00'::timestamp,'2008-01-01 01:00', '1 minute');
select * from generate_series('2008-01-01 00:00'::timestamp,'2008-01-01 12:00', '1 hour');
select * from generate_series('2008-01-01 00:00'::timestamp,'2009-01-01 12:00', '1 day');
select * from generate_series('2008-01-01 00:00'::timestamp,'2009-01-01 12:00', '1 week');
select * from generate_series('2008-01-01 00:00'::timestamp,'2009-01-01 12:00', '1 month');
select * from generate_series('2008-01-01 00:00'::timestamp,'2009-01-01 12:00', '1 year');
select * from generate_series('2008-01-01 00:00'::timestamp,'2009-01-01 12:00', '1 decade');
select * from generate_series('2008-01-01 00:00'::timestamp,'2009-01-01 12:00', '1 century');
select * from generate_series('2008-01-01 00:00'::timestamp,'2009-01-01 12:00', '1 millennium');

如果quarter不能使用，那么最好的其他选择是什么？目前，我有：

select 
   date_trunc('quarter',generate_series) gs 
from 
   generate_series('2008-01-01 00:00'::timestamp,'2009-01-01 12:00', '1 month') 
group by 
   gs
order by
   gs;
4

1 回答 1

14

这不应该做你所期望的：

SELECT * FROM generate_series('2008-01-01 00:00'::timestamp,
                              '2009-01-01 12:00', '3 months');

结果：

   生成系列   
---------------------
 2008-01-01 00:00:00
 2008-04-01 00:00:00
 2008-07-01 00:00:00
 2008-10-01 00:00:00
 2009-01-01 00:00:00
(5 行)
于 2013-06-28T13:05:30.343 回答