SSRS Query Where clause

In The SQL SERVER ::

Where C.name IN (@country) AND (R.first_name like ISNULL( @firstName , '%%') )

AND (R.last_name like ISNULL(@lastName , '%%') )

AND (R.company_name like ISNULL( @CompanyName , '%%'))

AND ( R.email like ISNULL ( @email , '%%') )

In The Oracle ::

Where C.name IN (:country)

or

FROM TWITTER

where date_created >= :startdate and date_created <= :enddate

and channel like nvl(:channel,'%%')

and username like nvl(:username,'%%')

order by date_created asc

------> above :enddate parameter's default value '=Today()'

Sum Total:

[="Total Logins : "&Sum(Fields!No_of_Unique_Logins.Value)]

Count Total:

[="Total Users : "&count(Fields!USERNAME.Value)]

Execution Time:

="Executed On @ " + Format(Globals!ExecutionTime,"dd/MM/yyyy hh:mm:ss tt")

Report Properties:

Tital = 'Normal, Tahoma, 13pt, Medium'

Column='Normal, Cambria, 11pt, Bold'

value field='Normal, Verdana, 10pt, Normal'