MyBatis中带条件的多表分页查询

1.两个表对应的实体

public class Subarea implements Serializable{
    private String id;

    private String decidedzoneId;

    private String regionId;

    private String addresskey;

    private String startnum;

    private String endnum;

    private String single;

    private String position;

    //封装和区域表的联查结果
    private  Region  region;
        ...
        ...
        ...
}



public class Region implements Serializable{
    private String id;

    private String province;

    private String city;

    private String district;

    private String postcode;

    private String shortcode;

    private String citycode;


            ...
            ...
            ...
}

1.Controller 

 /**
     * 分页查询
     * @return
     */
    @RequestMapping("/SubAreaController/list.action")
    @ResponseBody
    public PageBean list(Subarea subarea,@RequestParam(defaultValue = "1") Integer page,
                         @RequestParam(defaultValue = "10")Integer rows) throws Exception {
        PageBean pageBean = new PageBean();
        pageBean.setCurrentPage(page);
        pageBean.setPageSize(rows);
        if(subarea.getRegion() == null){
            subAreaService.list(pageBean);
        }else{
            subAreaService.selectByConditions(pageBean,subarea);
        }
        return pageBean;
    }

2.service层

 /**
     * 带条件的分页查询
     * @param pageBean
     * @param subarea
     * @throws Exception
     */
    @Override
    public void selectByConditions(PageBean pageBean, Subarea subarea) throws Exception {
        PageHelper.startPage(pageBean.getCurrentPage(),pageBean.getPageSize());
        List<Subarea> subareas = subareaMapper.selectByConditions(subarea);
        PageInfo<Subarea> subareaPageInfo = new PageInfo<>(subareas);
        pageBean.setTotal(subareaPageInfo.getTotal());
        pageBean.setRows(subareaPageInfo.getList());
    }

3.Mapper接口

 List<Subarea> selectByConditions(Subarea subarea);

4.Mapper.xml文件

  <resultMap id="selectByConditionsResult" type="com.jujung.bos.pojo.Subarea">
    <id column="id" property="id"/>
    <result column="regionId" property="regionId"/>
    <result column="addresskey" property="addresskey"/>
    <result column="startnum" property="startnum"/>
    <result column="endnum" property="endnum"/>
    <result column="single" property="single"/>
    <result column="position" property="position"/>
    <association property="region" javaType="com.jujung.bos.pojo.Region">
      <!--
        column:指关联对象数据库中字段名
        property:指关联对象在实体中属性名
      -->
      <id column="region_id" property="id"/>
      <result column="province" property="province"/>
      <result column="city" property="city"/>
      <result column="district" property="district"/>
    </association>
  </resultMap>
  <select id="selectByConditions" parameterType="com.jujung.bos.pojo.Subarea" resultMap="selectByConditionsResult">
    SELECT t1.id,t1.region_id,t1.addresskey,t1.startnum,t1.endnum,t1.single,t1.position,t2.province,t2.city,t2.district
    FROM bc_subarea t1 INNER JOIN bc_region t2
    ON t1.region_id =  t2.id
    <where>
      <if test="region.province != null">
       AND t2.province like '%${region.province}%'
      </if>
      <if test="region.city != null">
        AND t2.city like '%${region.city}%'
      </if>
      <if test="region.district != null">
        AND t2.district like '%${region.district}%'
      </if>
      <if test="addresskey != null">
        AND t1.addresskey like '%${addresskey}%'
      </if>
    </where>
  </select>