sql语句报无效的关系运算图 类型是biginteger

  select * from thickness_matching_t
    where  THICKNESS_GROUP_MAIN_ID='16168406821569334'   and
     (( best_thick_min <= '1' and best_thick_max =>'1') or
     (best_thick_min<= '2' and best_thick_max =>'2') or
       ('1'<= best_thick_min and '1' =>best_thick_max ) or
        ('2'<= best_thick_min and '2' =>best_thick_max ))

=>这个我猜是>=吧？