select a from table1 where(条件)
如果有记录显示查询出来的记录，如果没有记录显示“无”，如下所示
有记录： 无记录：
a a
---------- ----------
a1 无
a2
a3
...
------解决方案--------------------
if exists(select 1 from table1)
select * from table1
else
select '无 ' from table1
------解决方案--------------------
create table table1(a varchar(8))
insert table1 select 'a1 '
union all select 'a2 '
union all select 'a3 '
go
if exists(select * from table1 where a= 'a1 ')
select * from table1 where a= 'a1 '
else
select top 1 '无 ' as a from table1
if exists(select * from table1 where a= 'a4 ')
select * from table1 where a= 'a4 '
else
select top 1 '无 ' as a from table1
drop table table1