Spring-SpringMVC-Mybatis框架下的 省市区 三级联动 第二版

一年前写过一篇关于省市区三级联动的,当时的那篇  省  市  区 分为了三张表,但现实工作中,往往是单张表 ,然后自己查自己.

现在我以这样的情况重写写一篇.

先看看表结构

这里我们关注主键Id,名称以及父级Id

在这里我们能看到,我们表中 将 省 市 区/县   都写在了一张表内,通过父级Id建立连接.

实体类根据Mybatis逆向工程来生成,除了表中属性外  添加一个额外的属性  List childrenList;

public class ShoppingArea {
	//主键Id
    private Long id;
    private Date addtime;
    private Boolean deletestatus;
    private String areaname;
    private Integer level;
    private Integer sequence;
    //父级Id
    private Long parentId;
    private Boolean common;

    //子级列表   非表属性
    private List<ShoppingArea> childrenList;
    //getter
    //setter
}

在逆向工程生成的Dao层接口mapper.java如下:

public interface ShoppingAreaMapper {
    int deleteByPrimaryKey(Long id);

    int insert(ShoppingArea record);

    int insertSelective(ShoppingArea record);

    ShoppingArea selectByPrimaryKey(Long id);

    int updateByPrimaryKeySelective(ShoppingArea record);

    int updateByPrimaryKey(ShoppingArea record);
    
    //根据父级id找子级
    List<ShoppingArea> selectByParentId(Long parentId);
    
    //查询所有
    List<ShoppingArea> selectAll();
    
}

mapper.xml如下:

<mapper namespace="com.test.dao.ShoppingAreaMapper" >

	<resultMap id="BaseResultMap" type="com.test.entity.ShoppingArea" >
	    <id column="id" property="id" jdbcType="BIGINT" />
	    <result column="addTime" property="addtime" jdbcType="TIMESTAMP" />
	    <result column="deleteStatus" property="deletestatus" jdbcType="BIT" />
	    <result column="areaName" property="areaname" jdbcType="VARCHAR" />
	    <result column="level" property="level" jdbcType="INTEGER" />
	    <result column="sequence" property="sequence" jdbcType="INTEGER" />
	    <result column="parent_id" property="parentId" jdbcType="BIGINT" />
	    <result column="common" property="common" jdbcType="BIT" />
	</resultMap>

  <resultMap id="BaseResultMapProvenice" type="com.test.entity.ShoppingArea" extends="BaseResultMap" >
	<collection property="childrenList" ofType="com.test.entity.ShoppingArea" column="id" 
	select="com.test.dao.ShoppingAreaMapper.selectByParentIdOfCity" javaType="java.util.ArrayList" >
		 <id column="id" property="id" jdbcType="BIGINT" />
	    <result column="addTime" property="addtime" jdbcType="TIMESTAMP" />
	    <result column="deleteStatus" property="deletestatus" jdbcType="BIT" />
	    <result column="areaName" property="areaname" jdbcType="VARCHAR" />
	    <result column="level" property="level" jdbcType="INTEGER" />
	    <result column="sequence" property="sequence" jdbcType="INTEGER" />
	    <result column="parent_id" property="parentId" jdbcType="BIGINT" />
	    <result column="common" property="common" jdbcType="BIT" />
  	</collection>
  </resultMap>
  
  <resultMap id="BaseResultMapCity" type="com.test.entity.ShoppingArea" extends="BaseResultMap" >
	<collection property="childrenList" ofType="com.test.entity.ShoppingArea" column="id" 
	select="com.test.dao.ShoppingAreaMapper.selectByParentIdOfArea" javaType="java.util.ArrayList" >
		 <id column="id" property="id" jdbcType="BIGINT" />
	    <result column="addTime" property="addtime" jdbcType="TIMESTAMP" />
	    <result column="deleteStatus" property="deletestatus" jdbcType="BIT" />
	    <result column="areaName" property="areaname" jdbcType="VARCHAR" />
	    <result column="level" property="level" jdbcType="INTEGER" />
	    <result column="sequence" property="sequence" jdbcType="INTEGER" />
	    <result column="parent_id" property="parentId" jdbcType="BIGINT" />
	    <result column="common" property="common" jdbcType="BIT" />
  	</collection>
  </resultMap>
  
  
  
  
  <sql id="Base_Column_List" >
    id, addTime, deleteStatus, areaName, level, sequence, parent_id, common
  </sql>
  
  
  <select id="selectAll" resultMap="BaseResultMapProvenice"  >
    select 
    <include refid="Base_Column_List" />
    from shopping_area 
    where parent_id is null
  </select>
  
  
  <select id="selectByPrimaryKey" resultMap="BaseResultMapProvenice" >
    select 
    <include refid="Base_Column_List" />
    from shopping_area
    where id = #{id,jdbcType=BIGINT}
  </select>
  
  
  <select id="selectByParentIdOfCity" resultMap="BaseResultMapCity"  >
    select 
    <include refid="Base_Column_List" />
    from shopping_area
    where parent_id = #{parentId,jdbcType=BIGINT}
  </select>
  
  
  
  <select id="selectByParentIdOfArea" resultMap="BaseResultMap"  >
    select 
    <include refid="Base_Column_List" />
    from shopping_area
    where parent_id = #{parentId,jdbcType=BIGINT}
  </select>
  
  

 

看上图即可.

测试代码:

 

结果如下:

打断点,直接看生成的结果

查询所有:

获取单个省级实体