or的用法
select * from bt where bt.ID =98 or bt.ID = 1222 or bt.ID = 8903;
in 的用法
select * from bt where bt.ID in (98 ,1222 ,8903);
union all 的用法
select * from bt where bt.ID=98 union all select * from bt where bt.ID=1222 union all select * from bt where bt.ID=8903;