kylin query with case return error result

[徐 鹏]

HI all:
        Query1:
                SELECT  COUNT(DISTINCT CASE WHEN pagefiltername IN (‘homepage') 
THEN t.loginkey END) AS homepageuv
                FROM fly t
                WHERE yyyymmdd='20161222’  
        Query2:
                SELECT COUNT(DISTINCT t.loginkey ) AS homepageuv FROM fly t 
WHERE yyyymmdd='20161222' and pagefiltername IN ('homepage') ;

        expected :Query1=Query2
        actual:Query1 !=Query2

        What’s wrong?


Regards,
Peng Xu
xupeng1...@outlook.com