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Person<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!--
Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping package="com.me.blog.bean">
<class name="Person" table="person">
<id name="id" type="java.lang.Integer">
<column name="ID" />
<generator class="native" />
</id>
<property name="name" type="java.lang.String">
<column name="name" length="0" />
</property>
<one-to-one name="idcard" property-ref="person" cascade="all"></one-to-one>
</class>
</hibernate-mapping>IdCard<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!--
Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping package="com.me.blog.bean">
<class name="Idcard" table="idcard">
<id name="id" type="java.lang.Integer">
<column name="id" />
<generator class="native" />
</id>
<property name="idCard" type="java.lang.String">
<column name="idCard" length="0" />
</property>
<many-to-one name="person" column="personId" unique="true" />
</class>
</hibernate-mapping>
查询了下列表
结果hibernate
Hibernate: select person0_.ID as ID62_, person0_.name as name62_ from person person0_ limit ?
Hibernate: select idcard0_.id as id61_0_, idcard0_.idCard as idCard61_0_, idcard0_.personId as personId61_0_ from idcard idcard0_ where idcard0_.personId=?
Hibernate: select idcard0_.id as id61_0_, idcard0_.idCard as idCard61_0_, idcard0_.personId as personId61_0_ from idcard idcard0_ where idcard0_.personId=?
Hibernate: select idcard0_.id as id61_0_, idcard0_.idCard as idCard61_0_, idcard0_.personId as personId61_0_ from idcard idcard0_ where idcard0_.personId=?
Hibernate: select count(person0_.ID) as col_0_0_ from person person0_
这也太可怕了,主表查询一条where 有一万的记录 岂不是 从表也要查询 1w个查询
请问该怎么优化下~ 谢谢!!!
但是B又没有持有A那么B的映射就是many-to-one因为B不确定是有一个A持有它还是多个按楼主的意思是想做双向一对一在数据库中B也要关联到A