Question

I’ve got query

SELECT frst.Date,t1.Value
from
[ArchiveAnalog] frst
LEFT JOIN
    (SELECT Date,Value FROM
    [ArchiveAnalog] scnd
    WHERE scnd.ID = 1) t1
    ON t1.Date = frst.Date

order by frst.Date

but Join inserts values second time (not group with a main node)

if I do GROUP BY frst.Date , I’ve got error that I can’t use t1 Value with it.

How can I make this JOIN without adding additional rows ?

Martin I want to show full Date and Value only if ID = 1 , also then I want to add t2 value column etc like here :

SELECT frst.Date,t1.Value,t2.Value
from
[ArchiveAnalog] frst
LEFT JOIN
    (SELECT Date,Value FROM
    [ArchiveAnalog] scnd
    WHERE scnd.ID = 1) t1
    ON t1.Date = frst.Date
LEFT JOIN
(SELECT Date,Value FROM
[ArchiveAnalog] scnd
WHERE scnd.ID = 2) t2
ON frst.Date = t2.Date

here I have x2 additional rows :S with doubling values, so I need to group them all with a some way.

Answer 1

Does this do what you need?

SELECT Date , 
       MAX(CASE WHEN ID=1 THEN Value END) AS val1,
       MAX(CASE WHEN ID=2 THEN Value END) AS val2
FROM [ArchiveAnalog]
WHERE ID IN (1,2) /*<-- Not sure if you need this line without seeing your data*/
GROUP BY Date