Element-ui(Cascader 级联选择器)实现三级联动

Posted 2023-03-17

1：将省市县数据三张表存放到数据库中

市区表：

CREATE TABLE `med_cities` (
  `id` int(11) NOT NULL AUTO_INCREMENT COMMENT 主键,
  `cityid` char(6) NOT NULL COMMENT 城市编码,
  `city` varchar(40) NOT NULL COMMENT 城市名称,
  `provinceid` char(6) NOT NULL COMMENT 所属省份编码,
  PRIMARY KEY (`id`) USING BTREE
) ENGINE=InnoDB AUTO_INCREMENT=346 DEFAULT CHARSET=utf8 ROW_FORMAT=COMPACT COMMENT=城市信息表;

县区表：

CREATE TABLE `med_areas` (
  `id` int(11) NOT NULL AUTO_INCREMENT COMMENT 主键,
  `areaid` char(6) NOT NULL COMMENT 区县编码,
  `area` varchar(40) NOT NULL COMMENT 区县名称,
  `cityid` char(6) NOT NULL COMMENT 所属城市编码,
  PRIMARY KEY (`id`) USING BTREE
) ENGINE=InnoDB AUTO_INCREMENT=3145 DEFAULT CHARSET=utf8 ROW_FORMAT=COMPACT COMMENT=区县信息表;

省级表：

CREATE TABLE `med_provinces` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `provinceid` int(11) NOT NULL,
  `province` varchar(100) NOT NULL DEFAULT ,
  PRIMARY KEY (`id`) USING BTREE
) ENGINE=MyISAM AUTO_INCREMENT=392 DEFAULT CHARSET=utf8 ROW_FORMAT=DYNAMIC;

2：在后端处理省市县所对应的数据

Controller层：

/**
 * @Author 爱吃豆的土豆、
 * @Date 2023/3/10 10:45
 */
@RestController
@RequestMapping("/provinces")
public class ProvincesController 
    @Resource
    private ProvincesService provincesService;

    @GetMapping
    public BaseResult findAllprovinces()
        List<MedProvinces> provincesList = provincesService.findAllprovinces();
        if (provincesList != null)
            return BaseResult.ok("查询成功",provincesList);
        else 
            return BaseResult.error("查询失败");
        
    

service层

/**
 * @Author 爱吃豆的土豆、
 * @Date 2023/3/10 10:46
 */
public interface ProvincesService extends IService<MedProvinces> 
    List<MedProvinces> findAllprovinces();

serviceimpl实现

@Service
public class ProvincesServiceImpl extends ServiceImpl<ProvincesMapper,MedProvinces> implements ProvincesService 

    @Override
    public List<MedProvinces> findAllprovinces() 
        List<MedProvinces> allprovince = this.baseMapper.findAllprovince();
        return allprovince;
    

mapper层实现

映射省下面所有的市

/**
 * @Author 爱吃豆的土豆、
 * @Date 2023/3/10 10:33
 */
@Mapper
public interface ProvincesMapper extends BaseMapper<MedProvinces> 
    @Select("select * from med_provinces")
    @Results(
            @Result(property = "id",column = "id"),
            @Result(property = "provinceid",column = "provinceid"),
            @Result(property = "province",column = "province"),
            @Result(property = "children",column = "provinceid",many = @Many(select = "com.czxy.medical.mapper.CitiesMapper.findAllCity"))
    )
    public List<MedProvinces> findAllprovince();

映射市下面所有的县

/**
 * @Author 爱吃豆的土豆、
 * @Date 2023/3/10 10:35
 */
@Mapper
public interface CitiesMapper extends BaseMapper<MedCities> 
    @Select("SELECT * FROM med_cities WHERE med_cities.provinceid = #provinceid")
    @Results(
            @Result(property = "id",column = "id"),
            @Result(property = "cityid",column = "cityid"),
            @Result(property = "city",column = "city"),
            @Result(property = "provinceid",column = "provinceid"),
            @Result(property = "children",column = "cityid",many = @Many(select = "com.czxy.medical.mapper.AreasMapper.findAllArea"))
    )
    public List<MedCities> findAllCity(@Param("provinceid") Integer provinceid);


 

查询所有的区县

/**
 * @Author 爱吃豆的土豆、
 * @Date 2023/3/10 10:33
 */
@Mapper
public interface AreasMapper extends BaseMapper<MedAreas> 
    @Select("SELECT * FROM med_areas WHERE cityid = #cityid")
    public List<MedAreas> findAllArea(@Param("cityid") Integer cityid);

对应的省JavaBean

@Data
@TableName(value = "med_provinces")
public class MedProvinces 
  @TableId(type = IdType.AUTO,value = "id")
  private Integer id;

  @JsonProperty("value")
  @TableField(value = "provinceid")
  private Integer provinceid;

  @JsonProperty("label")
  @TableField(value = "province")
  private String province;

  @TableField(exist = false)
  private List<MedCities> children = new ArrayList<>();

对应市JavaBean

@Data
@TableName(value = "med_cities")
public class MedCities 
  @TableId(type = IdType.AUTO,value = "id")
  private Integer id;

  @JsonProperty("value")
  @TableField(value = "cityid")
  private Integer cityid;

  @JsonProperty("label")
  @TableField(value = "city")
  private String city;

  @JsonProperty("pid")
  @TableField(value = "provinceid")
  private Integer provinceid;

  @TableField(exist = false)
  private List<MedAreas> children = new ArrayList<>();

对应的县区JavaBean

@Data
@TableName(value = "med_areas")
public class MedAreas 
  @TableId(value = "id", type = IdType.AUTO)
  private Integer id;

  @JsonProperty("value")
  @TableField(value = "areaid")
  private String areaid;

  @JsonProperty("label")
  @TableField(value = "area")
  private String area;

  @TableField(value = "cityid")
  private Integer cityid;

3：Cascader 级联选择器，进行回显操作

级联选择器

<el-cascader
                    v-model="value"
                    :options="placeList"
                    size="medium"
                    :props="
                      expandTrigger: hover,
                    "
                    @change="handleChange">
                  </el-cascader>

data() 
    return 
      value: [],
      placeList: []
    ;
  ,

方法：

methods: 
    handleChange(value) 
      console.log(value);
    ,
    async findAllplaceFn() 
      let data: baseResult = await this.$request.findAllplace()
      this.placeList = baseResult.data
    
  ,

注意：级联选择器需要保持和后端映射保持一致回显数据

element-ui官网级联选择器示例：

element-ui之级联选择器(Cascader) 全选 功能

最近产品要求做一个省市区选择，效果就建议使用element-UI的cascader级联，这也是我第一次使用此插件，但要在原cascader级联基础上加一个“全选”按钮，查看官方文档没有关于全选功能属性设置。搜索也没找到好的方法解决。最后请教一个大牛，下面是实现全选的方法.
(官方文档地址：https://element.eleme.cn/#/zh-CN/component/cascader)
方法就是：从树结构中抽出数据。变与model结构就可以了。

需要引用（官方可下载）：
<script src="js/vue.js"></script>
<script src="js/index.js"></script>
 <link rel="stylesheet" href="css/index.css">

JS代码：

var data = [{
    id: 1,
    name: \'东南\',
    children: [{
        id: 2,
        name: \'上海\',
        children: [
            { id: 3, name: \'普陀\' },
            { id: 4, name: \'黄埔\' },
            { id: 5, name: \'徐汇\' }
        ]
    }, {
        id: 7,
        name: \'江苏\',
        children: [
            { id: 8, name: \'南京\' },
            { id: 9, name: \'苏州\' },
            { id: 10, name: \'无锡\' }
        ]
    }, {
        id: 12,
        name: \'浙江\',
        children: [
            { id: 13, name: \'杭州\' },
            { id: 14, name: \'宁波\' },
            { id: 15, name: \'嘉兴\' }
        ]
    }]
}, {
    id: 17,
    name: \'西北\',
    children: [{
        id: 18,
        name: \'陕西\',
        children: [
            { id: 19, name: \'西安\' },
            { id: 20, name: \'延安\' }
        ]
    }, {
        id: 21,
        name: \'新疆维吾尔族自治区\',
        children: [
            { id: 22, name: \'乌鲁木齐\' },
            { id: 23, name: \'克拉玛依\' }
        ]
    }]
}];

var Main = {
    data() {
        return {
            check: false,
            casVal: [],
            quchong: [],
            props: {
                multiple: true,
                value: \'id\',
                label: \'name\'
            },
            options: data
        };
    },
    computed: {
        allCheckValues() {
            var model = []
            function tree2arr(arr, str, level) {
                arr.forEach(it => {
                    let newStr = str.length ? [...str, it.id] : [it.id];
                    if (it.children) {
                        tree2arr(it.children, newStr, level + 1)
                    } else {
                        model.push(newStr)
                    }
                })
            }
            tree2arr(this.options, [], 0)
            return model
        },
    },
    methods: {
        onCheck(v) {
            this.casVal = v ? this.allCheckValues : []
            console.log(this.casVal)
        },
        handleChange(value) {
            let selectVal = value;
            this.allCheckValues.length==selectVal.length?this.check = true : this.check = false;
            console.log(selectVal, \'选中的vlaue值\')
        },
    }
};
var Ctor = Vue.extend(Main)
new Ctor().$mount(\'#app\')