Hibernate(HQL) 奇异的count()函数

<query name="getRecordCountById">
	select count(1) as recordCount from Km c
	where c.id=:id
</query>

<query name="getRecordCountById">
	select count(c.*) as recordCount from Km c
	where c.id=:id
</query>

<query name="getRecordCountById">
	select count(*) as recordCount from Km c
	where c.id=:id
</query>