带有索引标记的行的 postgresql 副本

Question

有没有办法让sql查询返回拆分行。我什至不知道怎么问。下面有'index_tag'。

select event.name, tb_ev.start_time, tb_ev.end_time
from block as tb_ev,event
where location_id in ( 28522 ) 
and tb_ev.event_id=event.id;

name           | start_time | end_time 
---------------+------------+---------- 
 Register #1   | 06:00:00   | 09:00:00
 Register #2   | 11:00:00   | 12:00:00
 Register #3   | 11:00:00   | 14:00:00

从3行到7行

 name          | start_time | end_time | index_tag
---------------+------------+-------------------- 
 Register #1   | 06:00:00   | 09:00:00 | 06:00:00
 Register #1   | 06:00:00   | 09:00:00 | 07:00:00
 Register #1   | 06:00:00   | 09:00:00 | 08:00:00
 Register #2   | 11:00:00   | 12:00:00 | 11:00:00
 Register #3   | 11:00:00   | 14:00:00 | 11:00:00
 Register #3   | 11:00:00   | 14:00:00 | 12:00:00
 Register #3   | 11:00:00   | 14:00:00 | 13:00:00

Answer 1

试试这个:

SELECT *, start_time +
          generate_series(0,extract(hour from (end_time - start_time))::int -1)
          * interval '1 hour' as index_tag
FROM block

它有点难看，但它有效(generate_series 不适用于 time。仅 int 或 timestamp).

这是 SQLFiddle

关于 generate_series 的详细信息