Spring-SpringMVC-Mybatis框架下的 省市區 三級聯動 第二版

一年前寫過一篇關於省市區三級聯動的,當時的那篇  省  市  區 分爲了三張表,但現實工作中,往往是單張表 ,然後自己查自己.

現在我以這樣的情況重寫寫一篇.

先看看錶結構

這裏我們關注主鍵Id,名稱以及父級Id

在這裏我們能看到,我們表中 將 省 市 區/縣   都寫在了一張表內,通過父級Id建立連接.

實體類根據Mybatis逆向工程來生成,除了表中屬性外  添加一個額外的屬性  List childrenList;

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

    //子級列表   非表屬性
    private List<ShoppingArea> childrenList;
    //getter
    //setter
}

在逆向工程生成的Dao層接口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);
    
    //根據父級id找子級
    List<ShoppingArea> selectByParentId(Long parentId);
    
    //查詢所有
    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>
  
  

 

看上圖即可.

測試代碼:

 

結果如下:

打斷點,直接看生成的結果

查詢所有:

獲取單個省級實體