Major Description
sql("""
with va as (
select '123' id, 'a' name
union all
select '123' id, 'b' name
)
select '123' id, 'a' name from va t where t.name = 'a'
minus
select '123' id, 'a' name from va s where s.name = 'b'
""").show
-----+
| id | name |
-----+
| 123 | a |
-----+
which is expected to be empty result set.