我在使用Hibernate时遇到了问题。当我想要将一个对象保存到数据库时,出现了以下异常:
org.hibernate.exception.GenericJDBCException: could not get next sequence value
25P02, current transaction is aborted, commands ignored until end of transaction block
我的Hibernate配置文件如下:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory name="">
<!-- Database connection settings -->
<property name="connection.driver_class">org.postgresql.Driver</property>
<property name="connection.url">jdbc:postgresql://localhost:5432/3encult</property>
<property name="connection.username">3encult</property>
<property name="connection.password">3encult</property>
<!-- JDBC connection pool (use the built-in) -->
<property name="connection.pool_size">10</property>
<!-- SQL dialect -->
<property name="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</property>
<!-- Enable Hibernate's automatic session context management -->
<property name="current_session_context_class">thread</property>
<!-- Disable the second-level cache
Echo all executed SQL to stdout -->
<property name="show_sql">true</property>
<!-- Drop and re-create the database schema on startup
<property name="hbm2ddl.auto">create</property>-->
<mapping resource="resources/User.hbm.xml"/>
<mapping resource="resources/ApplicationField.hbm.xml"/>
<mapping resource="resources/Attribute.hbm.xml"/>
<mapping resource="resources/Device.hbm.xml"/>
<mapping resource="resources/Role.hbm.xml"/>
</session-factory>
</hibernate-configuration>
并且我的Hibernate映射文件:
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated 07-abr-2011 13:29:19 by Hibernate Tools 3.4.0.CR1 -->
<hibernate-mapping>
<class name="com.cartif.database.Attribute" table="Attribute">
<id name="iAttrId" column="attributeid" type="java.lang.Integer">
<generator class="native">
<param name="sequence">s_attribute</param>
</generator>
</id>
<property column="name" generated="never" lazy="false" name="name" type="java.lang.String"/>
<property column="value" generated="never" lazy="false" name="value" type="java.lang.String"/>
<property column="timestamp" generated="never" lazy="false" name="date" type="java.sql.Timestamp"/>
<property column="deviceId" generated="never" lazy="false" name="iDeviceId" type="java.lang.Integer"/>
<property column="sensorId" generated="never" lazy="false" name="iSensorId" type="java.lang.Integer"/>
</class>
</hibernate-mapping>
属性 iAttrId 存在并且它有 get/set 方法,表 Attribute 上也存在列 attributeid。
Hibernate 显示 SQL 查询语句,它们是:
Hibernate: select nextval ('s_attribute')
Hibernate: insert into Attribute (name, value, timestamp, deviceId, sensorId, attributeid) values (?, ?, ?, ?, ?, ?)
什么是原因?
谢谢!