所以我正在使用 spring 数据,并且在尝试获取此休眠查询的列表时遇到问题。
interface NewFooWithMetadataDAO : Repository<Foo, Int> {
@Query("""SELECT NEW com.foo.persistence.sql.po.NewFooWithMetadataPO(
b.id,
b.accountId,
bi.profitCenterSegmentation,
b.fooContext
)
from
Foo b
left join b.fooIntent bi
left join b.fooContext bc
where
account_id = ?1
group by
b.id
""")
fun findByAccountId(accountId: Int): List<NewFooWithMetadataPO>
}
此查询创建一个像这样的休眠查询。
select
foo0_.id as col_0_0_,
foo0_.account_id as col_1_0_,
foo_buc1_.profit_center_segmentation as col_2_0_,
. as col_3_0_
from
foo foo0_
left outer join foo_intent foo_buc1_ on foo0_.foo_intent_id=foo_buc1_.id
left outer join foo_context_map foocont2_ on foo0_.id=foocont2_.foo_id
inner join foo_context_map foocont3_ on foo0_.id=foocont3_.foo_id
where
account_id=?
group by foo0_.id
这是一个错误的查询。
我还在 HQL 中尝试了 bc
而不是 b.fooContext
,但是我没有得到集合,而是得到了一个 FooContextPO。
我的实体就像
@Entity
@Table(name = "foo")
data class Foo(
@Id
val id: Int,
@Column(name= "account_id")
val accountId: Int,
@OneToOne
@JoinColumn(name = "foo_intent_id", referencedColumnName = "id")
@NotFound(action=NotFoundAction.IGNORE)
val fooIntent: FooIntentPO,
@OneToMany
@JoinColumn(name = "foo_id", referencedColumnName = "id")
@NotFound(action=NotFoundAction.IGNORE)
val fooContext: Collection<FooContextPO>
){
@Entity
@Table(name = "foo_intent")
data class FooIntentPO(
@Id
val id: Int,
@Column(name = "profit_center_segmentation")
val profitCenterSegmentation: String
)
@Entity
@Table(name = "foo_context_map")
data class FooContextPO(
@Id
val id: Int,
@Column(name = "foo_id")
val fooId: Int,
@OneToOne
@JoinColumn(name = "context_id", referencedColumnName = "id")
val context: ContextPO
)
@Entity
@Table(name = "context")
data class ContextPO (
@Id
val id: Int,
@ManyToOne
@JoinColumn(name = "foo_id", referencedColumnName = "id")
val foo: Foo,
@Column(name = "context")
val context: String
)
}
data class NewFooWithMetadataPO(
val id: Int,
val accountId: Int?,
val profitCenterSegmentation: String?,
val context: Collection<Foo.FooContextPO>
)
有什么方法可以让左连接在这里正常工作而不生成内连接吗?
最佳答案
由于选择下面的映射属性b.fooContext
,您肯定会获得内部连接
SELECT NEW com.foo.persistence.sql.po.NewFooWithMetadataPO(
b.id,
b.accountId,
bi.profitCenterSegmentation,
b.fooContext
)...
您将作为 bc
单独外部联接到 FooContextPO
,因此如果您想避免内部联接,则无法引用映射的属性 fooContext
>。因此您需要选择 bc
。
事实上,由于实际的基础数据,您只得到 1 条记录吗?当您选择 bc 而不是 b.fooContext 时生成的 SQL 看起来也不正确吗?如果是这样...你能分享一下那个sql是什么样的吗?
关于mysql - Spring Data 在 OneToMany 上创建内部联接,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/45337304/