You can add a trailing '%' to your query. Assume that @param
is the parameter to your stored procedure:
declare @param2 varchar(100)
set @param2 = @param + '%'
select * from table where column like @param2
That will return a wildcard search beginning with the value in @param. For partial match use '%' + @param + '%'
[Edit]
Based on the below clarification in the comments:
if @id != '*'
begin
select * from table where column = @id
end
else
begin
select * from table
end