grouping select query

Hi,
I have data stored as in below sample :
--+--+--
--
DateBegin | DateEnd | Rate
--+--+--
--
2005-11-13 00:00:00 2005-11-14 00:00:00 63.0000
2005-11-14 00:00:00 2005-11-15 00:00:00 63.0000
2005-11-15 00:00:00 2005-11-16 00:00:00 45.0000
2005-11-16 00:00:00 2005-11-17 00:00:00 45.0000
2005-11-17 00:00:00 2005-11-18 00:00:00 45.0000
2005-11-18 00:00:00 2005-11-19 00:00:00 45.0000
2005-11-19 00:00:00 2005-11-20 00:00:00 45.0000
2005-11-20 00:00:00 2005-11-21 00:00:00 63.0000
2005-11-21 00:00:00 2005-11-22 00:00:00 63.0000
--+--+--
--
I have to group the select query in this way :
--+--+--
--
DateBegin | DateEnd | Rate
--+--+--
--
2005-11-13 00:00:00 2005-11-15 00:00:00 63.0000
2005-11-15 00:00:00 2005-11-20 00:00:00 45.0000
2005-11-20 00:00:00 2005-11-22 00:00:00 63.0000
--+--+--
--
When I run below grouped statement, I get follewed result:
SELECT MIN(DateBegin) AS DateBegin, MAX(DateEnd) AS DateEnd,
Rate FROM X GROUP BY Rate
--+--+--
--
DateBegin | DateEnd | Rate
--+--+--
--
2005-11-13 00:00:00 2005-11-22 00:00:00 63.0000
2005-11-15 00:00:00 2005-11-20 00:00:00 45.0000
--+--+--
--
How can I do a query like in 2nd sample from top?
best regards,
rustam bogubaevThis is a periodicity problem, not a SQL syntax problem.
You have to define how the period is to be divided first. In essence,
however you decide to calculate the period, the data would logically contain
the following information.
--+--+--
--
DateBegin | DateEnd | Rate |
Period
--+--+--
--
2005-11-13 00:00:00 2005-11-14 00:00:00 63.0000 1
2005-11-14 00:00:00 2005-11-15 00:00:00 63.0000 1
2005-11-15 00:00:00 2005-11-16 00:00:00 45.0000 2
2005-11-16 00:00:00 2005-11-17 00:00:00 45.0000 2
2005-11-17 00:00:00 2005-11-18 00:00:00 45.0000 2
2005-11-18 00:00:00 2005-11-19 00:00:00 45.0000 2
2005-11-19 00:00:00 2005-11-20 00:00:00 45.0000 2
2005-11-20 00:00:00 2005-11-21 00:00:00 63.0000 3
2005-11-21 00:00:00 2005-11-22 00:00:00 63.0000 3
--+--+--
--
With the periods defined, however that is done, your problem will be easy.
Perhaps something like the following would help find the boundarys of the
periods.
SELECT b.DateBegin
FROM MyTable a JOIN MyTable b
ON a.DateEnd = b.DateBegin
WHERE a.Rate != b.Rate
RLF
<rustam.bogubaev@.gmail.com> wrote in message
news:1131461007.812709.108200@.g49g2000cwa.googlegroups.com...
> Hi,
> I have data stored as in below sample :
> --+--+--
--
> DateBegin | DateEnd | Rate
> --+--+--
--
> 2005-11-13 00:00:00 2005-11-14 00:00:00 63.0000
> 2005-11-14 00:00:00 2005-11-15 00:00:00 63.0000
> 2005-11-15 00:00:00 2005-11-16 00:00:00 45.0000
> 2005-11-16 00:00:00 2005-11-17 00:00:00 45.0000
> 2005-11-17 00:00:00 2005-11-18 00:00:00 45.0000
> 2005-11-18 00:00:00 2005-11-19 00:00:00 45.0000
> 2005-11-19 00:00:00 2005-11-20 00:00:00 45.0000
> 2005-11-20 00:00:00 2005-11-21 00:00:00 63.0000
> 2005-11-21 00:00:00 2005-11-22 00:00:00 63.0000
> --+--+--
--
>
> I have to group the select query in this way :
> --+--+--
--
> DateBegin | DateEnd | Rate
> --+--+--
--
> 2005-11-13 00:00:00 2005-11-15 00:00:00 63.0000
> 2005-11-15 00:00:00 2005-11-20 00:00:00 45.0000
> 2005-11-20 00:00:00 2005-11-22 00:00:00 63.0000
> --+--+--
--
> When I run below grouped statement, I get follewed result:
> SELECT MIN(DateBegin) AS DateBegin, MAX(DateEnd) AS DateEnd,
> Rate FROM X GROUP BY Rate
> --+--+--
--
> DateBegin | DateEnd | Rate
> --+--+--
--
> 2005-11-13 00:00:00 2005-11-22 00:00:00 63.0000
> 2005-11-15 00:00:00 2005-11-20 00:00:00 45.0000
> --+--+--
--
> How can I do a query like in 2nd sample from top?
> best regards,
> rustam bogubaev
>|||On 8 Nov 2005 06:43:27 -0800, rustam.bogubaev@.gmail.com wrote:
(snip)
>I have to group the select query in this way :
>--+--+--
--
> DateBegin | DateEnd | Rate
>--+--+--
--
>2005-11-13 00:00:00 2005-11-15 00:00:00 63.0000
>2005-11-15 00:00:00 2005-11-20 00:00:00 45.0000
>2005-11-20 00:00:00 2005-11-22 00:00:00 63.0000
>--+--+--[/c
olor]
Hi rustam,
If my assumptions about your table and the reasons for your expected
results are correct, then try:
SELECT a.DateBegin, MAX(b.DateEnd), a.Rate
FROM X AS a
INNER JOIN X as b
ON b.Rate = a.Rate
AND b.DateBegin >= a.DateStart
WHERE NOT EXISTS
(SELECT *
FROM X AS c
WHERE c.DateBegin = DATEADD(day, -1, a.DateBegin)
AND c.Rate = a.Rate)
AND NOT EXISTS
(SELECT *
FROM X AS d
WHERE d.DateBegin > a.DateEnd
AND d.DateEnd < b.DateBegin
AND d.Rate <> a.Rate)
GROUP BY a.DateBegin, a.Rate
(untested - see www.aspfaq.com/5006 if you prefer a tested reply)
Best, Hugo
--
(Remove _NO_ and _SPAM_ to get my e-mail address)