休眠使用 where 子句中的联接列创建查询

Question

我有一个表，其中表结构是这样的

package com.abc.domain;

@Entity
@Table(
    name = "ENTITY_DTL"
)
public class MyEntityDtl implements Serializable {
    private static final long serialVersionUID = 1L;
    private static final int NATLTY_CD_LENGTH = 3;

    @Id
    @Column(
        name = "MY_ENTITY_DTL_ID",
        unique = true,
        nullable = false
    )
    @GeneratedValue(
        strategy = GenerationType.SEQUENCE,
        generator = "myEntityDtlIdSeq"
    )
    @SequenceGenerator(
        name = "myEntityDtlIdSeq",
        sequenceName = "MY_ENTITY_DTL_ID_SEQ",
        allocationSize = 1
    )
    private Long MyEntityDtlId;

    @ManyToOne(
        fetch = FetchType.LAZY
    )
    @JoinColumns({@JoinColumn(
    name = "ENTITY_ID",
    referencedColumnName = "ENTITY_ID",
    nullable = false
), @JoinColumn(
    name = "ENTITY_TYPE_CD",
    referencedColumnName = "ENTITY_TYPE_CD",
    nullable = false
)})
    private MyEntity myEntity;

    /* 
    other columns and their getter setter 
    */

}

在这里 - 我想要实现的是 - 像这样

使用此列将 MyEntityDtl 表与 Abc 表联接 - ENTITY_ID 和 ENTITY_TYPE_CD 。

如何在查询中不使用 MyEntity 表来实现它。

因为在这种情况下，这将花费我额外的加入

任何帮助不胜感激，提前谢谢

Answer 1

由于获取类型是懒惰的，我直接使用连接列来创建连接，它不会影响查询性能，因为获取类型 lzay -

 Query query = getEntityManager().createQuery("SELECT abc FROM ABC abc, MyEntityDtl medtl join medtl.myEntity  me " +
                        " WHERE vsf.rqstId = me.entityId AND  " +
                        " me.entityTypeCd = '?' AND " +
                        " medtl.SOME_OTHER_COLUMN= '?' " ;
                query.setParameter("entityTypeCd", VALUE);
                query.setParameter("SOME_OTHER_COLUMN", VALUE);