YuanGong.java 对象有以下属性
private int id;
private String name;
private String sal;
private String sex;
private Person person;
private List<Person> pList;Person.java对象
private int id;
private String name;
private int age;
private String sex;
private Date date;这里假设person的id，name跟YuanGong的id和name有关联，也就是说用yuangong表里面的id或者name能从perosn表里查到记录，且有一对多（所以会存在list属性）。
mybatis 配置 yuangong
<resultMap type="entiry.YuanGong" id="YGmapper">
<id property="id" column="id"/>
<result property="name" column="name"/>
<result property="sal" column="sal"/>
<result property="sex" column="sex"/>
<result property="sex" column="sex"/>
<association property="person" column="{tid=id,tname=name}" select="selectPerson"/>
<collection property="pList" ofType="entiry.Person"
select="selectPersonList" column="name" javaType="ArrayList"/>
</resultMap>person 配置
<resultMap type="entiry.Person" id="personM">
<id property="id" column="id"/>
<result property="name" column="name"/>
<result property="age" column="age"/>
<result property="sex" column="sex"/>
<result property="date" column="date" jdbcType="DATE"/>
</resultMap>两个select
<select id="selectPerson" parameterType="java.util.Map" resultMap="personM">
select * from PERSON where id=#{tid} and name=#{tname}
</select>
<select id="selectPersonList" parameterType="java.lang.String" resultMap="personM">
select * from PERSON where name=#{name}
</select>查询例子
<select id="selectEmp" parameterType="entiry.YuanGong" resultMap="YGmapper">
select * from yuangong
</select>其实这里配置映射主要就是association 跟collection 标签里面这个select=“selectPerson"属性
column=”{tid=id,tname=name}"表示
map.put(“tid”,yuangong.id);
map.put(“tname”,yuangong.name);
然后执行
<select id="selectPerson" parameterType="java.util.Map" resultMap="personM">
select * from PERSON where id=#{tid} and name=#{tname}
</select>传入的map里面就有对应的tid值跟tname值了。
执行selectEmp，
可以看到日志分别执行了三段sql
select * from yuangong；
select * from PERSON where name=#{name}；
select * from PERSON where id=#{tid} and name=#{tname}；
debugger模式下可以看到yuangong对象属性都有值了