Something like this should be very close at least, I think:

create proc pSearch

@searchparam varchar(400) -- values will be entered like this - seperated by comma: John, Mary, 23.10.1980

as

set @searchparam = @searchparam + ','

declare @value varchar(100)

set @value = ''

-- create temp table to enter search values separated in rows

create table #search(value varchar(100) primary key)

-- insert each unique value into #search

while charindex(',',@searchparam)> 0

begin

set @value = left(@searchparam, charindex(',',@searchparam)-1)

set @searchparam = ltrim(right(@searchparam,len(@searchparam) - charindex(',',@searchparam)))

insert into #search select @value where not exists ( select 1 from #search where value = @value )

end

UPDATE STATISTICS #search WITH FULLSCAN

-- return all clients which match any one of the search criteria with like operator

select distinct c.id, c.firstname, c.lastname, c.birthdate

from dbo.tblclient c

inner join #search s on

c.Firstname like s.value

or c.Lastname like s.value

or c.birthdate like s.value

go