select Case with subqueries select and using Top

Hi i want to retrive the list of browsers used by user id

Table Contains

UserID int

BrowserName nvarchar(40)

here is my Query

select browser =
CASE
    WHEN ( PATINDEX('%IE%',BrowserName) IS not null)  THEN   SUBSTRING(BrowserName,PatIndex('%IE%',BrowserName),8) 
   WHEN (PATINDEX('%Firefox%',BrowserName) IS not null)  THEN SUBSTRING(BrowserName,PatIndex('%Firefox%',BrowserName),8)
   WHEN (PATINDEX('%Chrome%',BrowserName) IS not null)  THEN SUBSTRING(BrowserName,PatIndex('%Chrome%',BrowserName),6)
END



from tableBrowsers where UserId =21 

But how to select only top 1 substring in this query .

eg : after when in case statement i n need only one row returned for that case, i tried this, but not getting idea how to implement in case

THEN   select top 1 SUBSTRING(BrowserName,PatIndex('%IE%',BrowserName),8)  from browsertable

out开发者_高级运维put will be like this

IE

FIREFOX

CHROME

if the user used three browsers

Just add DISTINCT:

SELECT DISTINCT browser = 
CASE 
    WHEN ( PATINDEX('%IE%',BrowserName) IS not null)  THEN   SUBSTRING(BrowserName,PatIndex('%IE%',BrowserName),8)  
   WHEN (PATINDEX('%Firefox%',BrowserName) IS not null)  THEN SUBSTRING(BrowserName,PatIndex('%Firefox%',BrowserName),8) 
   WHEN (PATINDEX('%Chrome%',BrowserName) IS not null)  THEN SUBSTRING(BrowserName,PatIndex('%Chrome%',BrowserName),6) 
END 
FROM tableBrowsers where UserId =21