Hiberante 类型问题
映射文件extends.hbm.xml如下：
<hibernate-mapping package="com.bjsxt.hibernate">
<class name="Animal" table="t_animal" lazy="false">
<id name="id">
<generator class="native"/>
</id>
<discriminator column="type" type="String"/>
<property name="name"/>
<property name="sex"/>
<subclass name="Pig" discriminator-value="P">
<property name="weight"/>
</subclass>
<subclass name="Bird" discriminator-value="B">
<property name="height"/>
</subclass>
</class>
</hibernate-mapping>
执行ExportDB后出现下面的错误提示：
Exception in thread "main" org.hibernate.MappingException: Could not determine type for: String, for columns: [org.hibernate.mapping.Column(type)]
at org.hibernate.mapping.SimpleValue.getType(SimpleValue.java:266)
at org.hibernate.mapping.Column.getSqlTypeCode(Column.java:138)
at org.hibernate.mapping.Column.getSqlType(Column.java:182)
at org.hibernate.mapping.Table.sqlCreateString(Table.java:383)
at org.hibernate.cfg.Configuration.generateSchemaCreationScript(Configuration.java:779)
at org.hibernate.tool.hbm2ddl.SchemaExport.<init>(SchemaExport.java:94)
at org.hibernate.tool.hbm2ddl.SchemaExport.<init>(SchemaExport.java:61)
at com.bjsxt.hibernate.ExportDB.main(ExportDB.java:13)
映射文件extends.hbm.xml修改如下：
<hibernate-mapping package="com.bjsxt.hibernate">
<class name="Animal" table="t_animal" lazy="false">
<id name="id">
<generator class="native"/>
</id>
<discriminator column="type" type="string"/>
<property name="name"/>
<property name="sex"/>
<subclass name="Pig" discriminator-value="P">
<property name="weight"/>
</subclass>
<subclass name="Bird" discriminator-value="B">
<property name="height"/>
</subclass>
</class>
</hibernate-mapping>
ExportDB正常导出。分析原因：type指的是hibernate中的类型，不是java中的String类型，必须小写，同样如integer也是要小写。