How to manage two tables in SQL Server i have two tables offer1 and offer2 

The two tables are 

Offer1 
Offer2ID|OfferName|OfferExpiryDate

Offer2
Offer2ID|OfferName|OfferExpiryDate


now i have third table which keeps record 

offersentdetail 
offerID|senttime|sentCount|UserID 


now i want output sent on Specifc userID 

Output will be like 

UserID | OfferID | OfferName
Try this:

select osd.UserId, osd.OfferId, ou.OfferName
  from dbo.offersentdetail as osd
    inner join (
      select OfferId = Offer1Id, OfferName, OfferExpiryDate
        from dbo.[Offer1] 
      union all 
      select OfferId = Offer2Id, OfferName, OfferExpiryDate
        from dbo.[Offer2] 
        ) as ou
    on osd.OfferId = ou.OfferId