休眠多对多

Question

我有三个表和两个JPA模型类：

Unit
------------
id [PK]    - Integer
code       - String
unitGroups - List<UnitGroup>


UnitGroup
------------
id [PK]    - Integer
ugKey      - String
units      - List<Unit>

units和unitGroups之间有多对多的关系。 简单地说，我想编写一个HQL查询来获取以下sql的输出：

SELECT u.* 
FROM units u, unit_groups ug, unit_group_pairs ugp 
WHERE ugp.UnitID = u.ID 
AND ugp.UnitGroupID = ug.ID 
AND ug.UGKey = 'amount' AND u.ID = 10

Answer 1

我希望这会奏效，但不确定。请不要否定:)。我自己没试过这个。想出这个，所以它可能对你有所帮助。欢呼声。

from Unit as units 
inner join fetch units.unitGroups grp
inner join fetch grp.units
where grp.ugKey = 'amount' and units.id = 10

Answer 2

最后：

select u from Unit u left join u.unitGroups ug where u.id = 10 and ug.ugKey = 'amount'

Answer 3

试试这个

select u from  unit as u 
where u.ID = 10 and 
'amount' = any elements(u.unitGroups.UGKey)