--> 测试数据：[test]
if object_id('[test]') is not null drop table [test]
create table [test](
[A1] varchar(50),
[A2] varchar(10),
[A3] varchar(50),
[A4] varchar(8)
)
insert [test]
select null,null,'368bc947-1c49-463f-a612-f1731d05d90d','氨苄西林' union all
select '40d19a4c-758f-4992-90a2-f1b9569f78bc','青霉素类','40d19a4c-758f-4992-90a2-f1b9569f78bc','青霉素类' union all
select '4d59154b-09e4-4413-836a-09b34651f589','阿莫西林','4d59154b-09e4-4413-836a-09b34651f589','阿莫西林' union all
select 'e5ba770f-5374-4340-bbff-cfcaa2e81203','药物处方集',null,null


select *from(
select [A1] as BH,[A2] as NAME from [test] union
select [A3],[A4] from [test])a
where BH is not null
/*
BH    NAME
368bc947-1c49-463f-a612-f1731d05d90d    氨苄西林
40d19a4c-758f-4992-90a2-f1b9569f78bc    青霉素类
4d59154b-09e4-4413-836a-09b34651f589    阿莫西林
e5ba770f-5374-4340-bbff-cfcaa2e81203    药物处方集
*/