when is select records no record found

Question

i have table like this below.....

sno   name     mobile
1       raju       9xx393xxxx
2      vamshi    9856784562

iam using below quarie

select * from  tablename where mobile='9856784562'    

its shows no records found...

but iam using below quarie is shows the record.........

select * from tablename where mobile like '%9856784562%' 

it's working ..................

 what is the wrong on first quarie ...

 plz tell what is the error ..................