Question

我写了一个映射如下：

<hibernate-mapping auto-import="true" default-lazy="false">
    <class name="com.saman.entity.hibernate.EmployeeEntity"
           table="Employee" optimistic-lock="version">

        <id name="id" type="java.lang.Integer" >
            <column name="Id" />
            <generator class="identity"/>
        </id>
        <timestamp name="version" source="db"/>
        <property  name="firstName">
            <column name="FirstName" sql-type="nvarchar(300)"/>
        </property>
        <property name="lastName">
            <column name="LastName" sql-type="nvarchar(300)"/>
        </property>
        <property name="employeeType">
            <column name="EmployeeType" sql-type="nvarchar(300)"/>
        </property>
        <!--
        <set name="shifts" table="Shifts" inverse="true" lazy="true" fetch="select">
            <key>
                <column name="Id" not-null="true"/>
            </key>
            <one-to-many class="com.saman.entity.hibernate.ShiftEntity"/>
        </set>
        -->
        <properties name="u1" unique="true">
            <property name="firstName"/>
            <property name="lastName"/>
            <property name="employeeType"/>
        </properties>

    </class>
</hibernate-mapping>

当我运行我的应用程序时，会出现如下错误：

2012-05-15 17：12：38,651 - 警告 - 不成功的架构语句：create table Employee（Id integer not null auto_increment，version datetime not null，FirstName nvarchar（300），LastName nvarchar（300），EmployeeType nvarchar（300），主键（Id），唯一（firstName，lastName，employeeType）） com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException：指定的键太长;最大密钥长度为1000字节 at sun.reflect.NativeConstructorAccessorImpl.newInstance0（Native Method） at sun.reflect.NativeConstructorAccessorImpl.newInstance（NativeConstructorAccessorImpl.java:39） at sun.reflect.DelegatingConstructorAccessorImpl.newInstance（DelegatingConstructorAccessorImpl.java:27） at java.lang.reflect.Constructor.newInstance（Constructor.java:513）在com.mysql.jdbc.Util.handleNewInstance（Util.java:411）在com.mysql.jdbc.Util.getInstance（Util.java:386）在com.mysql.jdbc.SQLError.createSQLException（SQLError.java:1052）在com.mysql.jdbc.MysqlIO.checkErrorPacket（MysqlIO.java:3609）在com.mysql.jdbc.MysqlIO.checkErrorPacket（MysqlIO.java:3541）在com.mysql.jdbc.MysqlIO.sendCommand（MysqlIO.java:2002）在com.mysql.jdbc.MysqlIO.sqlQueryDirect（MysqlIO.java:2163）在com.mysql.jdbc.ConnectionImpl.execSQL（ConnectionImpl.java:2618）在com.mysql.jdbc.StatementImpl.executeUpdate（StatementImpl.java:1749）在com.mysql.jdbc.StatementImpl.executeUpdate（StatementImpl.java:1666）在com.mchange.v2.c3p0.impl.NewProxyStatement.executeUpdate（NewProxyStatement.java:64）在org.springframework.orm.hibernate3.LocalSessionFactoryBean.executeSchemaStatement（LocalSessionFactoryBean.java:1115）在org.springframework.orm.hibernate3.LocalSessionFactoryBean.executeSchemaScript（LocalSessionFactoryBean.java:1087）在org.springframework.orm.hibernate3.LocalSessionFactoryBean $ 1.doInHibernate（LocalSessionFactoryBean.java:942）在org.springframework.orm.hibernate3.HibernateTemplate.doExecute（HibernateTemplate.java:406）在org.springframework.orm.hibernate3.HibernateTemplate.execute（HibernateTemplate.java:339）在org.springframework.orm.hibernate3.LocalSessionFactoryBean.updateDatabaseSchema（LocalSessionFactoryBean.java:935）在org.springframework.orm.hibernate3.LocalSessionFactoryBean.afterSessionFactoryCreation（LocalSessionFactoryBean.java:883）在org.springframework.orm.hibernate3.AbstractSessionFactoryBean.afterPropertiesSet（AbstractSessionFactoryBean.java:213）在org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods（AbstractAutowireCapableBeanFactory.java:1477）在org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean（AbstractAutowireCapableBeanFactory.java:1417）在org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean（AbstractAutowireCapableBeanFactory.java:519）在org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean（AbstractAutowireCapableBeanFactory.java:456） at org.springframework.beans.factory.support.AbstractBeanFactory $ 1.getObject（AbstractBeanFactory.java:291）在org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton（DefaultSingletonBeanRegistry.java:222）在org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean（AbstractBeanFactory.java:288）在org.springframework.beans.factory.support.AbstractBeanFactory.getBean（AbstractBeanFactory.java:190） at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons（DefaultListableBeanFactory.java:563）在org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization（AbstractApplicationContext.java:895）在org.springframework.context.support.AbstractApplicationContext.refresh（AbstractApplicationContext.java:425）在org.springframework.context.support.ClassPathXmlApplicationContext。（ClassPathXmlApplicationContext.java:139）在org.springframework.context.support.ClassPathXmlApplicationContext。（ClassPathXmlApplicationContext.java:83）在Main.main（Main.java:18）

它有什么问题？

我使用mysql并在MAMP上运行它。

Answer 1

MyISAM引擎存在已知问题。您可以尝试使用此link将引擎更改为InnoDB：

Answer 2

指定的密钥太长;最大密钥长度为1000字节

此错误表示您的唯一索引（firstName，lastName，employeeType）超过1000个字节，这是最大值。来自mysql文档

"UTF-8 encoding of the Unicode character set using one to three bytes per character"

因此，您可以看到您有三个300长度的字段，因此您的索引大小可以是300 * 3 * 3 = 2700＆gt; 1000

hibernate映射创建表

2 个答案: