我有一个包含以下类的模型:
public class Organization {
private Person person;
}
public class PersonAddress {
private Person person;
private Address address;
}
public class Address {
...
}
Person 和 Address、Person 和 PersonAddress、Address 和 PersonAddress 之间没有直接关联。 PersonAddress 是 Person 和 Address 之间的多对多关联，但我们试图避免映射相应的集合，因为滥用它们可能会导致一些性能问题。
我正在尝试创建一个 querydsl 方法，将组织作为参数传递，并使用组织、人员和地址数据获取预计结果，但迄今为止我最好的尝试是使用交叉联接提供查询。
我能否以避免交叉联接的方式构建此查询？并且还避免创建集合关联。
这是 querydsl 查询和生成的 SQL:
查询DSL:
QOrganization organization = QOrganization.organization;
QPerson person = QPerson.person;
QPerson personOrganization = new QPerson("personOrganization");
QAddressPerson addressPerson = QAddressPerson.addressPerson;
QAddress address = QAddress.address;
QCity city = QCity.city;
JPQLQuery<Organization> query = newQuery().from(addressPerson,organization)
.join(organization.person, person)//
.join(addressPerson.address, address)//
.join(address.city, city)//
.leftJoin(addressPerson.person, personOrganization);
BooleanBuilder builder = new BooleanBuilder();
builder.and(organization.eq(organizationParam));
query.where(builder)//
.select(create(organization.id, organization.type, //
QPerson.create(person.id, person.type, //
QAddressPerson.create(addressPerson.id, //
QAddress.create(address.id, //
QCity.create(city.id, city.name), address.zipcode)))));
生成的 SQL:
select
organization1_.org_id as col_0_0_,
organization1_.org_tp as col_1_0_,
person2_.pes_id as col_4_0_,
person2_.pes_tp as col_5_0_,
addresspe0_.enp_id as col_10_0_,
address3_.end_id as col_11_0_,
city4_.cid_id as col_12_0_,
city4_.cid_nm as col_13_0_,
address3_.END_VR_CEP as col_15_0_
from
address_person addresspe0_
inner join
address address3_
on addresspe0_.end_id=address3_.end_id
inner join
city city4_
on address3_.cid_id=city4_.cid_id
left outer join
person person5_
on addresspe0_.pes_id=person5_.pes_id cross
join
organization organization1_
inner join
person person2_
on organization1_.pes_id=person2_.pes_id
where
and organization1_.org_id=?
最佳答案
这部分导致交叉连接
newQuery().from(addressPerson,organization)
您需要将 addressPerson 或 organization 移动到内部联接或左联接。
关于java - 使用多个 ManyToOne 连接进行查询，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/31125024/