模糊查询的SQL有关问题

模糊查询的SQL问题
notes         id
NULL DTHX15020500001
NULL DTHX15020900001
test345 DTHX15021500001
NULL DTHX15021500003
test123 DTHX15021600001
NULL DTHX15032300001
NULL HX15032600005
NULL HX15032600006

想模糊查找NOTEs不等于test123

NULL DTHX15020500001
NULL DTHX15020900001
test345 DTHX15021500001
NULL DTHX15021500003
NULL DTHX15032300001
NULL HX15032600005
NULL HX15032600006
------解决思路----------------------
select * from tablename where isnull(NOTEs,'')<>'test123'