未在表opendb-city-china内发现合法的父子关系标识parentKey

数据表opendb-city-china.schema.json定义如下

{  
  "schema": {  
    "bsonType": "object",  
    "required": ["code", "name"],  
    "permission": {  
        "read": true,  
        "create": false,  
        "update": false,  
        "delete": false  
    },  
    "properties": {  
      "_id": {  
        "description": "ID，系统自动生成"  
      },  
      "code": {  
        "bsonType": "string",  
        "description": "编码"  
      },  
      "parent_code": {  
        "bsonType": "string",  
        "description": "父级编码",  
        "parentKey": "code"  
      },  
      "name": {  
        "bsonType": "string",  
        "description": "城市名称",  
        "title": "城市"  
      },  
      "type": {  
        "bsonType": "int",  
        "description": "城市类型；0省，1市，2区"  
      },  
      "first_letter": {  
        "bsonType": "string",  
        "description": "拼音首字母"  
      },  
      "pinyin": {  
        "bsonType": "string",  
        "description": "城市名称的完整汉语拼音，用于拼音检索"  
      },  
      "zip_code": {  
        "bsonType": "string",  
        "description": "邮政编码",  
        "title": "邮编"  
      }  
    }  
  },  
  "index": [  
    {  
      "IndexName": "code_",  
      "MgoKeySchema": {  
        "MgoIndexKeys": [{  
          "Name": "code",  
          "Direction": "1"  
        }],  
        "MgoIsUnique": true  
      }  
    },  
    {  
      "IndexName": "name",  
      "MgoKeySchema": {  
        "MgoIndexKeys": [{  
          "Name": "name",  
          "Direction": "1"  
        }],  
        "MgoIsUnique": false  
      }  
    },  
    {  
      "IndexName": "first_letter",  
      "MgoKeySchema": {  
        "MgoIndexKeys": [{  
          "Name": "first_letter",  
          "Direction": "1"  
        }],  
        "MgoIsUnique": false  
      }  
    },  
    {  
      "IndexName": "pinyin",  
      "MgoKeySchema": {  
        "MgoIndexKeys": [{  
          "Name": "pinyin",  
          "Direction": "1"  
        }],  
        "MgoIsUnique": false  
      }  
    },  
    {  
      "IndexName": "parent_code",  
      "MgoKeySchema": {  
        "MgoIndexKeys": [{  
          "Name": "parent_code",  
          "Direction": "1"  
        }],  
        "MgoIsUnique": false  
      }  
    },  
    {  
      "IndexName": "zip_code",  
      "MgoKeySchema": {  
        "MgoIndexKeys": [{  
          "Name": "zip_code",  
          "Direction": "1"  
        }],  
        "MgoIsUnique": false  
      }  
    }  
  ]  
}

错误信息如下

      </uni-data-picker>