SQl Query Help.

Hi Friends

     I want to make my query like below output.

   Out put should be like this below.

    ID    String

     1      U

     2      UU

     3     UUU

     it means if ID is 1 then it should in string column only 1 U if it is 2 id then it should be 'UU'    and so on.

     what i use in the query  Select id from employee.

      Thanks,