帮助解决SQL Server查询条件

in

declare @lastName varchar(20)
set @lastName = \'Davis\'

select *
from Table1 
where Date >= \'2013-01-09\'  
and lastname in( 
    case 
    when @lastName = \'DAvis\' THEN @lastName 
    else \'Brown\',\'Hudson\' end)

select *
from Table1 
where 
    Date >= \'2013-01-09\' and
    (
        (@lastName = \'Davis\' and lastname = @lastName) or 
        (@lastName <> \'Davis\' and lastname in (\'Brown\',\'Hudson\'))
    )

declare @lastName varchar(20)
set @lastName = \'Davis\'

select * from Table1 

where Date >= \'2013-01-09\'  
and lastname in(
         \'DAvis\' ,\'Brown\',\'Hudson\')