>>>Try the following Statement, which error do you receive?
>>>
>>>CREATE VIEW Test
>>>AS SELECT Date, DatePart(hour,Date) as Hr, reading
>>>FROM TABLE1 A
>>>WHERE Date IN
>>>(SELECT Min(Date) as date
>>>FROM TABLE1 B
>>>WHERE DatePart(hour,A.Date) = DatePart(hour,B.Date)
>>>UNION
>>>SELECT Min(Date) as date
>>>FROM TABLE2 C
>>>WHERE DatePart(hour,A.Date) = DatePart(hour,C.Date))
>>
>>
>>Sir view created but when I try to click on design then it display error message shown in attachment.
>
>Interesting, could be the following case:
>
>https://stackoverflow.com/questions/28226369/i-have-a-view-that-runs-fine-when-executed-but-when-i-try-to-open-it-in-design

Yes, most of SQL Server professionals (including Erland Sommarskog) avoid using designers.