oracle Hibernate 中使用注解的复合主键
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Compound Primary Key in Hibernate using Annotations
提问by Rich
I have a table which uses two columns to represent its primary key, a transaction id and then the sequence number.
我有一个表，它使用两列来表示其主键、一个事务 ID，然后是序列号。
I tried what was recommended http://docs.jboss.org/hibernate/stable/annotations/reference/en/html_single/#entity-mappingin section 2.2.3.2.2, but when I used the Hibernate session to commit this Entity object, it leaves out the TXN_ID field in the insert statement and only includes the BA_SEQ field!
我尝试了第 2.2.3.2.2 节中推荐的http://docs.jboss.org/hibernate/stable/annotations/reference/en/html_single/#entity-mapping，但是当我使用 Hibernate 会话提交此实体时对象，它忽略了插入语句中的 TXN_ID 字段，只包含 BA_SEQ 字段！
What's going wrong? Here's the related code excerpt:
怎么了？这是相关的代码摘录：
@Id
@Column(name="TXN_ID")
private long txn_id; public long getTxnId(){return txn_id;} public void setTxnId(long t){this.txn_id=t;}
@Id
@Column(name="BA_SEQ")
private int seq; public int getSeq(){return seq;} public void setSeq(int s){this.seq=s;}
And here are some log statements to show what exactly happens to fail:
这里有一些日志语句来显示究竟发生了什么失败：
In createKeepTxnId of DAO base class: about to commit Transaction :: txn_id->90625
seq->0 ...<Snip>...
Hibernate: insert into TBL (BA_ACCT_TXN_ID, BA_AUTH_SRVC_TXN_ID, BILL_SRVC_ID,
BA_BILL_SRVC_TXN_ID, BA_CAUSE_TXN_ID, BA_CHANNEL, CUSTOMER_ID, BA_MERCHANT_FREETEXT,
MERCHANT_ID, MERCHANT_PARENT_ID, MERCHANT_ROOT_ID, BA_MERCHANT_TXN_ID, BA_PRICE,
BA_PRICE_CRNCY, BA_PROP_REQS, BA_PROP_VALS, BA_REFERENCE, RESERVED_1, RESERVED_2,
RESERVED_3, SRVC_PROD_ID, BA_STATUS, BA_TAX_NAME, BA_TAX_RATE, BA_TIMESTAMP, BA_SEQ)
values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
[WARN] util.JDBCExceptionReporter SQL Error: 1400, SQLState: 23000
[ERROR] util.JDBCExceptionReporter ORA-01400: cannot insert NULL into
("SCHEMA"."TBL"."TXN_ID")
The important thing to note is I print out the entity object which has a txn_id set, and then the following insert into statement does not include TXN_ID in the listing and thus the NOT NULL table constraint rejects the query.
需要注意的重要一点是我打印出设置了 txn_id 的实体对象，然后下面的 insert into 语句在列表中不包含 TXN_ID，因此 NOT NULL 表约束拒绝查询。
回答by Rich
how to make a composite primary key (java persistence annotation)
This helped.
这有帮助。
@IdClass(TxnPK.class)
and then defining a Serializable implementing class TxnPK with fields just like I wanted in my Entity class, as well as equals and hashCode methods.
然后定义一个 Serializable 实现类 TxnPK，其中的字段就像我在 Entity 类中想要的那样，以及 equals 和 hashCode 方法。
annotation on "secondary" fields of the primary key. So @Id on the BA_SEQ field. Also implemented hashCode and equals to supplement.
主键的“次要”字段注释。所以@Id 在 BA_SEQ 字段上。还实现了 hashCode 和 equals 补充。
回答by Bozho
Use @EmbeddedIdand @Embeddable. Roughly:
使用@EmbeddedId和@Embeddable。大致：
@EmbeddedId
private CompositeKey key;
@Embeddable
public class CompositeKey {
@Column
private int something;
@Column
private int somethingElse;
}
