Thread: union query doubt:

Hi;
I've got a table with three fields: DATE, POINT, FLOW. The POINT field can 
have values among 1 and 6. So, for a same date I have six different points 
with the correspondings flows.
I would like to make a query to obtain something like:
DATE POINT1 POINT2 POINT3 POINT4 POINT5 POINT6

where for a date I have the flows data of the different points.

I think that I would need to establish different alias for the same field. Is 
this possible?

Perhaps something like:

SELECT date, flow AS POINT1 FROM samples WHERE POINT=1 
UNION ALL
SELECT date, flow AS POINT2 FROM samples WHERE POINT=2
UNION ALL
SELECT date, flow AS POINT3 FROM samples WHERE POINT=3
...;

and a SELECT over the result of this subselect, that groups by date, or so?

Thanks for you help.

Javier

At 11:21 AM 12/11/02, javier garcia wrote:
>I've got a table with three fields: DATE, POINT, FLOW. The POINT field can
>have values among 1 and 6. So, for a same date I have six different points
>with the correspondings flows.
>I would like to make a query to obtain something like:
>DATE POINT1 POINT2 POINT3 POINT4 POINT5 POINT6
>
>where for a date I have the flows data of the different points.


SELECT date,
case when point = 1 then flow else 0 end as flow1,
case when point = 2 then flow else 0 end as flow2,
case when point = 3 then flow else 0 end as flow3,
case when point = 4 then flow else 0 end as flow4,
case when point = 5 then flow else 0 end as flow5,
case when point = 6 then flow else 0 end as flow6
from samples


There have been several messages recently about this - search on crosstab 
or pivot - a couple of other options were presented.

Frank

I think you meant:

SELECT date,
sum( case when point = 1 then flow else 0 end) as flow1,
sum( case when point = 2 then flow else 0 end) as flow2,
sum( case when point = 3 then flow else 0 end) as flow3,
sum( case when point = 4 then flow else 0 end) as flow4,
sum( case when point = 5 then flow else 0 end) as flow5,
sum( case when point = 6 then flow else 0 end) as flow6
from samples group by date;



Frank Bax wrote:
> 
> At 11:21 AM 12/11/02, javier garcia wrote:
> >I've got a table with three fields: DATE, POINT, FLOW. The POINT field can
> >have values among 1 and 6. So, for a same date I have six different points
> >with the correspondings flows.
> >I would like to make a query to obtain something like:
> >DATE POINT1 POINT2 POINT3 POINT4 POINT5 POINT6
> >
> >where for a date I have the flows data of the different points.
> 
> SELECT date,
> case when point = 1 then flow else 0 end as flow1,
> case when point = 2 then flow else 0 end as flow2,
> case when point = 3 then flow else 0 end as flow3,
> case when point = 4 then flow else 0 end as flow4,
> case when point = 5 then flow else 0 end as flow5,
> case when point = 6 then flow else 0 end as flow6
> from samples
> 
> There have been several messages recently about this - search on crosstab
> or pivot - a couple of other options were presented.
> 
> Frank
> 
> ---------------------------(end of broadcast)---------------------------
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