使用Sequelize ORM插入/更新PostGis几何 [英] Insert/Update PostGis Geometry with Sequelize ORM

问题描述

我用sequelize-auto提取了一些PostGis层的模型，给出了:

I have extracted models of some PostGis layers with sequelize-auto, giving:

module.exports = function(sequelize, DataTypes) {
return sequelize.define('table', {
  id: {
    type: DataTypes.INTEGER,
    allowNull: false,
    primaryKey: true,
    autoIncrement: true
  },
  geom: {
    type: DataTypes.GEOMETRY('POINT', 4326),
    allowNull: true,
  },
...

在GET sequelize上，将geom作为GeoJSON发送给客户端:

On GET sequelize sends the geom to the client as GeoJSON:

{
  "type":"Point",
  "coordinates":[11.92164103734465,57.67219297300486]
}

当我尝试通过以下方式保存此PosGis错误时:

When I try to save this back PosGis errors with:

ERROR:  Geometry SRID (0) does not match column SRID (4326)

该答案为如何添加SRID提供了一个指示(

This answer gives a god indication of how to add the SRID (How to insert a PostGIS GEOMETRY Point in Sequelize ORM?),

var point = { 
  type: 'Point', 
  coordinates: [39.807222,-76.984722],
  crs: { type: 'name', properties: { name: 'EPSG:4326'} }
};

User.create({username: 'username', geometry: point }).then(function(newUser) {
...
});

我了解SRID曾经是从sequelize中删除的功能( https://github .com/sequelize/sequelize/issues/4054 ).

I understand that SRID used to be a feature that was removed from sequelize (https://github.com/sequelize/sequelize/issues/4054).

有人知道钩住Sequelize的方法，以便将srid添加到发送给PostGis的GeoJson中吗?放在哪里?在模型的设定者中?

Does anyone know a way to hook into Sequelize so that the srid is added to the GeoJson sent to PostGis? Where to put it? In a setter on the model?

推荐答案

在保存GEOMETRY字段时，Sequelize似乎没有保存SRID(请注意，它正确地将SRID保存在GEOGRAPHY字段上).然后，当您将来更新该模型时，更新将失败，因为它没有在GEOMETRY字段中设置模型定义中预期的SRID.

It seems that Sequelize does not save the SRID when saving a GEOMETRY field (note, that it correctly saves the SRID on a GEOGRAPHY field). Then when you update that model in the future, the update will fail because it does not have a SRID set on the GEOMETRY field as expected in the model definition.

这不是理想的解决方案，但是您可以使用Sequelize的beforeSave挂钩始终指定要使用的坐标系.

This isn't a desirable solution, but you can use Sequelize's beforeSave hook to always speciify the coordinates system to use.

myDatabase.define('user', {
  name: {
    type: Sequelize.STRING
  },
  geometry: {
    type: Sequelize.GEOMETRY('POINT', 4326)
  }
}, {
  hooks: {
    beforeSave: function(instance) {
      if (instance.geometry && !instance.geometry.crs) {
        instance.geometry.crs = {
          type: 'name',
          properties: {
            name: 'EPSG:4326'
          }
        };
      }
    }
  }
});

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