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Union top 1

I am using union, like.

SELECT Id, StartDate From TableA
UNION
SELECT Id, StartDate From TableB

I would like to get top 1 ordered by StartDate. How is best to do this when I use Union?
0
johnkainn
Asked:
johnkainn
2 Solutions
 
sachitjainCommented:
Here it is

select top 1 Id, StartDate
from
      (SELECT Id, StartDate From TableA
      UNION
      SELECT Id, StartDate From TableB) L
order by StartDate
0
 
Scott PletcherSenior DBACommented:
This is potentially much better from a performance standpoint:


SELECT TOP 1 Id, StartDate
FROM (
    SELECT TOP 1 Id, StartDate
    From TableA
    ORDER BY StartDate
    UNION
    SELECT TOP 1 Id, StartDate
    From TableB
    ORDER BY StartDate
) AS derived
ORDER BY StartDate
0
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