如何将 GeoJSON 多边形数据发送到 typeorm (NestJS)？

Question

我想通过 POST 请求将 GeoJSON 多边形数据发送到 PostgresSQL。

因此，我尝试接收 Position[][] 类型并将其转换为 Polygon 类型，然后由 Postman 发送 POST 请求以进行 API 测试，但 我收到错误消息：“ QueryFailedError：无法在 GeoJSON 字符串中找到“坐标”。

有我的代码：

• 实体

   import { Column, Entity, Index, PrimaryGeneratedColumn } from "typeorm";
   import { Polygon } from "geojson";
  
   @Entity({ name: 'parcels' })
   export class Parcel {
  
       @PrimaryGeneratedColumn('uuid')
       id: string
  
       @Index({ spatial: true })
       @Column({
           type: 'geography',
           spatialFeatureType: 'Polygon',
           srid:4326,
           nullable: true
       })
       polygon: Polygon
  
   }
  

• Dto

   import { IsOptional } from "class-validator";
   import { Position } from "geojson";
  
   export class CreateParcelPointDto { 
       @IsOptional()
       position?: Position[][]
   }
  

• 控制器

   import { Body, Controller, Post } from '@nestjs/common';
   import { CreateParcelPointDto } from './dto/create-parcel-point.dto';
   import { Parcel } from './parcel.entity';
   import { ParcelService } from './parcel.service';
  
   @Controller('parcels')
   export class ParcelController {
       constructor(private parcelService: ParcelService) {}
  
       @Post()
       async createParcelPoint(
           @Body()
           createParcelPointDto: CreateParcelPointDto
       ): Promise<Parcel> {
           return this.parcelService.createParcelPoint(createParcelPointDto)
       }
   }
  

• 服务

   import { Injectable } from '@nestjs/common';
   import { InjectRepository } from '@nestjs/typeorm';
   import { Polygon } from 'geojson';
   import { CreateParcelPointDto } from './dto/create-parcel-point.dto';
   import { ParcelRepository } from './parcel.repository';
   import { Parcel } from './parcel.entity';
  
   @Injectable()
   export class ParcelService {
       constructor(
           @InjectRepository(ParcelRepository)
           private parcelRepository: ParcelRepository
       ) {}
  
       async createParcelPoint(createParcelPointDto: CreateParcelPointDto): Promise<Parcel> {
           const { position } = createParcelPointDto
  
           const polygon: Polygon = {
               type: 'Polygon',
               coordinates: position
           }
  
           const parcel = this.parcelRepository.create({
               polygon,
           })
  
           await this.parcelRepository.save(parcel)
           return parcel
       }
   }
  

• POST 请求 JSON

    {
        "polygon" : [
            [ 102.016680916961207, 14.876721809875564 ], 
            [ 102.016926580451127, 14.876676829236565 ], 
            [ 102.016936960598585, 14.876688939408604 ], 
            [ 102.017125533277465, 14.876656068941644 ], 
            [ 102.017130723351187, 14.876638768695875 ], 
            [ 102.017360816619913, 14.876598978130607 ], 
            [ 102.017243174948689, 14.87595713901259 ], 
            [ 102.017000971507926, 14.876002119651588 ], 
            [ 102.016994051409625, 14.875983089381243 ], 
            [ 102.016789908509551, 14.876022879946511 ], 
            [ 102.016786448460394, 14.876047100290586 ], 
            [ 102.016559815240825, 14.876090350905008 ], 
            [ 102.016680916961207, 14.876721809875564 ]
        ],
    }
  

我不知道如何通过 POST 请求将 GeoJSON 类型处理为 typeorm。如果有人有解决方案，请帮助我。

Answer 1

我已经解决了这个问题。在这种情况下，您需要将 Dto 中的类型定义为数字。维度必须与 Position 类型相同，并在创建 Polygon 对象时在坐标中增加一维。

例如，Polygon 类型需要接收 Position[][] 中的坐标。因此，您需要在 Dto 中将多边形定义为 number[][] 类型，并在创建 Polygon 对象时将坐标定义为 [polygon]。

代码示例：

• Dto

   import { IsOptional } from "class-validator";
  
   export class CreateParcelPointDto {
       @IsOptional()
       polygon?: number[][]
   }
  

• 服务

   import { Injectable } from '@nestjs/common';
   import { InjectRepository } from '@nestjs/typeorm';
   import { Polygon } from 'geojson';
   import { CreateParcelPointDto } from './dto/create-parcel-point.dto';
   import { ParcelRepository } from './parcel.repository';
   import { Parcel } from './parcel.entity';
  
   @Injectable()
   export class ParcelService {
       constructor(
           @InjectRepository(ParcelRepository)
           private parcelRepository: ParcelRepository
       ) {}
  
       async createParcelPoint(createParcelPointDto: CreateParcelPointDto): Promise<Parcel> {
           const {
               polygon,
           } = createParcelPointDto
  
           const polygonCreated: Polygon = {
               type: 'Polygon',
               coordinates: [polygon] //Need one more dimension here.
           }
  
           const parcel = this.parcelRepository.create({
               polygon: polygonCreated,
           })
  
           await this.parcelRepository.save(parcel)
           return parcel
       }
   }