我的代码中有一个com.mysql.jdbc.exceptions.MySQLIntegrityConstraintViolationException(使用Hibernate和Spring),我无法理解为什么。 我的实体是Corpus和Semspace,在我的hibernate映射配置中定义了从Semspace到Corpus的多对一关系:
<class name="xxx.entities.Semspace" table="Semspace" lazy="false" batch-size="30">
<id name="id" column="idSemspace" type="java.lang.Integer" unsaved-value="null">
<generator class="identity"/>
</id>
<property name="name" column="name" type="java.lang.String" not-null="true" unique="true" />
<many-to-one name="corpus" class="xxx.entities.Corpus" column="idCorpus"
insert="false" update="false" />
[...]
</class>
<class name="xxx.entities.Corpus" table="Corpus" lazy="false" batch-size="30">
<id name="id" column="idCorpus" type="java.lang.Integer" unsaved-value="null">
<generator class="identity"/>
</id>
<property name="name" column="name" type="java.lang.String" not-null="true" unique="true" />
</class>
生成异常的Java代码是:
Corpus corpus = Spring.getCorpusDAO().getCorpusById(corpusId);
Semspace semspace = new Semspace();
semspace.setCorpus(corpus);
semspace.setName(name);
Spring.getSemspaceDAO().save(semspace);
我检查了并且语料库变量不为空(因此它在数据库中使用DAO检索) 完整的例外是:
com.mysql.jdbc.exceptions.MySQLIntegrityConstraintViolationException: Cannot add or update a child row: a foreign key constraint fails (`xxx/Semspace`, CONSTRAINT `FK4D6019AB6556109` FOREIGN KEY (`idCorpus`) REFERENCES `Corpus` (`idCorpus`))
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:931)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2941)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1623)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1715)
at com.mysql.jdbc.Connection.execSQL(Connection.java:3249)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1268)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1541)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1455)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1440)
at org.apache.commons.dbcp.DelegatingPreparedStatement.executeUpdate(DelegatingPreparedStatement.java:102)
at org.hibernate.id.IdentityGenerator$GetGeneratedKeysDelegate.executeAndExtract(IdentityGenerator.java:73)
at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:33)
at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2158)
at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2638)
at org.hibernate.action.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:48)
at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:250)
at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:298)
at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:181)
at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:107)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:187)
at org.hibernate.event.def.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:33)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:172)
at org.hibernate.event.def.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:27)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:70)
at org.hibernate.impl.SessionImpl.fireSave(SessionImpl.java:535)
at org.hibernate.impl.SessionImpl.save(SessionImpl.java:523)
at org.hibernate.impl.SessionImpl.save(SessionImpl.java:519)
at org.springframework.orm.hibernate3.HibernateTemplate$12.doInHibernate(HibernateTemplate.java:642)
at org.springframework.orm.hibernate3.HibernateTemplate.execute(HibernateTemplate.java:373)
at org.springframework.orm.hibernate3.HibernateTemplate.save(HibernateTemplate.java:639)
at xxx.dao.impl.AbstractDAO.save(AbstractDAO.java:26)
at org.apache.jsp.functions.semspaceManagement_jsp._jspService(semspaceManagement_jsp.java:218)
[...]
外键约束已被hibernate创建(并添加到数据库),我看不出可以违反约束的位置。该表是innodb,我试图删除所有表并重新创建它,问题仍然存在......
编辑:嗯,我想我已经开始回答了...我将hibernate的日志级别更改为DEBUG,在崩溃之前我有以下日志insert into Semspace (name, [...]) values (?, [...])
所以看起来它不会尝试插入idCorpus,因为它不是null,它使用默认值“0”,它不引用Corpus表中的现有条目......
答案 0 :(得分:6)
我总是对关联映射感到困惑。查看所需的关联以及用于创建辅助的hibernate映射配置。
http://docs.jboss.org/hibernate/core/3.5/reference/en/html/associations.html
是一本很好的协会食谱书。
答案 1 :(得分:2)
这篇文章可能会有所帮助: http://www.javabeat.net/articles/42-integrating-spring-framework-with-hibernate-orm-framewo-1.html
答案 2 :(得分:1)
看起来很简单。您的例外的第一行明确指出违规行为是从idCorpus
列到另一个表Corpus/idCorpus
中的另一列。
您应该能够直接访问数据库以找出约束条件。我怀疑这是另一张桌子上的简单查找。
然后打印出你在提供的Java代码中使用的值,希望你能知道你试图在不在语料库中的Semspace中插入什么值。
com.mysql.jdbc.exceptions.MySQLIntegrityConstraintViolationException: Cannot add or update a child row: a foreign key constraint fails (
diaz/Semspace
, CONSTRAINT FK4D6019AB6556109
FOREIGN KEY (idCorpus
) REFERENCES Corpus
(idCorpus
))
答案 3 :(得分:1)
老帖子,我知道,但我发现所有这些解决方案都缺乏。
在hibernate映射中,您有:
<many-to-one name="corpus" class="xxx.entities.Corpus" column="idCorpus"
insert="false" update="false" />
您应该将第二行更改为:
<many-to-one name="corpus" class="xxx.entities.Corpus" column="idCorpus"
cascade="save-update" not-null="true" insert="true" />
答案 4 :(得分:0)
老帖子我知道,但是如果另一方是@ManyToOne的话,我有这个并通过将@ManyToMany更改为@OneToMany来修复它。