public class BeanName implements Serializable{  

	private String id;
	private String propertyName1;
	private String propertyName2;
	private String propertyName3;
	private String propertyName4;
	
    private List<PriceInfoDto> priceInfo;  //子集1 
  
    private List<NumInfoDto> numInfo;  //子集2
    
}  

public class PriceInfoDto implements Serializable{  
      
	private String id;
	private String name1;
	private String name2;
	private String name3;
	private String name4;
    
} 

public class NumInfoDto implements Serializable{  
      
	private String id;
	private String name5;
	private String name6;
	private String name7;
	private String name8;
    
} 

<select id="findInfo" parameterType="com.xx.xxx" resultMap="totalInfoMap">  
    select   
		total.id as id,  
		total.column_name1 as propertyName1,
		total.column_name2 as propertyName2,
		total.column_name3 as propertyName3,
		total.column_name4 as propertyName4,
		price.name1 as name1,   
		price.name2 as name2, 
		price.name3 as name3, 
		price.name4 as name4, 
		num.name5 as name5,   
		num.name6 as name6, 
		num.name7 as name7, 
		num.name8 as name8
    from table_total total left join table_num num on num.total_id = total.id   
		left join table_price price on price.total_id = total.id
	where total.status = 0
		and total.id = #{id} 
 </select>  


<resultMap type="com.xx.BeanName" id="totalInfoMap">  
        <!-- property ： bean中属性名称  column ： 表中字段名称 -->  
        <id property="id" column="id"/>  
        <result property="propertyName1" column="column_name1"/>  
        <result property="propertyName2" column="column_name2"/>  
        <result property="propertyName3" column="column_name3"/>  
        <result property="propertyName4" column="column_name4"/> 
        <!-- ofType bean属性名称 -->  
        <collection property="priceInfo" ofType="com.xx.PriceInfoDto">  
            <result property="name1" column="name1"/>  
            <result property="name2" column="name2"/>  
            <result property="name3" column="name3"/>  
            <result property="name4" column="name4"/>  
        </collection>   
        <collection property="numInfo" ofType="com.xx.NumInfoDto">  
            <result property="name5" column="name5"/>  
            <result property="name6" column="name6"/>  
            <result property="name7" column="name7"/>  
            <result property="name8" column="name8"/>  
        </collection>  
</resultMap>