DECLARE @vcDB varchar(20),@vcSchema varchar(20),@vcTable varchar(200)

Select @vcDB='mydb',@vcSchema='dbo'

DECLARE cLoop cursor for
  select TABLE_NAME
     from INFORMATION_SCHEMA.TABLES
     where TABLE_CATALOG=@vcDB
       and TABLE_SCHEMA=@vcSchema
     order by TABLE_NAME ASC

open cLoop

FETCH NEXT FROM cLoop INTO @vcTable
WHILE @@FETCH_STATUS=0
  BEGIN
    if not exists (SELECT *
           FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS
           WHERE TABLE_SCHEMA = @vcSchema
           AND   TABLE_NAME   = @vcTable
           AND   CONSTRAINT_TYPE = 'PRIMARY KEY')
      print @vcTable + ' does not have a primary key'

    FETCH NEXT FROM cLoop INTO @vcTable
   END
   Close cLoop
   DEALLOCATE cLoop

select TABLE_NAME from INFORMATION_SCHEMA.TABLES
where OBJECTPROPERTY(OBJECT_ID(TABLE_NAME),'TableHasPrimaryKey')=0