----创建测试数据
declare @t table(id int identity(1,1),DnName varchar(50))
insert @t(DnName)
select 'a|b|c|d|e|f|g|h|i|t|d|-|' union all
select 'a123,xyz' union all
select 'abcDeFgh' union all
select 'a-()*v'
----查询纯字符的行
select * from @t where patindex('%[^a-z]%',DnName) = 0
/*结果
id DnName
--------------------------------
3 abcDeFgh
*/