无法读取未定义的属性“连接器”

Question

 {
  "error": {
    "statusCode": 500,
    "name": "TypeError",
    "message": "Cannot read property 'connector' of undefined",
    "stack": "TypeError: Cannot read property 'connector' of undefined\n    at Function.Projects.getProjectData (F:\\SanWork\\AngularWorkSpace\\jobMngt\\common\\models\\projects.js:7:44)\n    at SharedMethod.invoke (F:\\SanWork\\AngularWorkSpace\\jobMngt\\node_modules\\strong-remoting\\lib\\shared-method.js:263:25)\n    at HttpContext.invoke (F:\\SanWork\\AngularWorkSpace\\jobMngt\\node_modules\\strong-remoting\\lib\\http-context.js:389:12)\n    at phaseInvoke (F:\\SanWork\\AngularWorkSpace\\jobMngt\\node_modules\\strong-remoting\\lib\\remote-objects.js:654:9)\n    at runHandler (F:\\SanWork\\AngularWorkSpace\\jobMngt\\node_modules\\loopback-phase\\lib\\phase.js:135:5)\n    at iterate (F:\\SanWork\\AngularWorkSpace\\jobMngt\\node_modules\\loopback-phase\\node_modules\\async\\lib\\async.js:146:13)\n    at Object.async.eachSeries (F:\\SanWork\\AngularWorkSpace\\jobMngt\\node_modules\\loopback-phase\\node_modules\\async\\lib\\async.js:162:9)\n    at runHandlers (F:\\SanWork\\AngularWorkSpace\\jobMngt\\node_modules\\loopback-phase\\lib\\phase.js:144:13)\n    at iterate (F:\\SanWork\\AngularWorkSpace\\jobMngt\\node_modules\\loopback-phase\\node_modules\\async\\lib\\async.js:146:13)\n    at F:\\SanWork\\AngularWorkSpace\\jobMngt\\node_modules\\loopback-phase\\node_modules\\async\\lib\\async.js:157:25\n    at F:\\SanWork\\AngularWorkSpace\\jobMngt\\node_modules\\loopback-phase\\node_modules\\async\\lib\\async.js:154:25\n    at execStack (F:\\SanWork\\AngularWorkSpace\\jobMngt\\node_modules\\strong-remoting\\lib\\remote-objects.js:493:7)\n    at RemoteObjects.execHooks (F:\\SanWork\\AngularWorkSpace\\jobMngt\\node_modules\\strong-remoting\\lib\\remote-objects.js:497:10)\n    at phaseBeforeInvoke (F:\\SanWork\\AngularWorkSpace\\jobMngt\\node_modules\\strong-remoting\\lib\\remote-objects.js:650:10)\n    at runHandler (F:\\SanWork\\AngularWorkSpace\\jobMngt\\node_modules\\loopback-phase\\lib\\phase.js:135:5)\n    at iterate (F:\\SanWork\\AngularWorkSpace\\jobMngt\\node_modules\\loopback-phase\\node_modules\\async\\lib\\async.js:146:13)"
  }
}

使用此代码时出现此错误，我想知道导致错误的原因以及任何可能的修复方法。

型号代码：

  'use strict';

module.exports = function(Projects) {
Projects.getProjectData = function(cb) {
        var sql = 'select * from projects';
        // call sql query from postreSQL
        Projects.app.datasources.postgres.connector.query(sql, function(err, result) {
            if (err) {
                console.log('Error retrieving projects result ...');
                console.log(err);
                return cb(err);
            }
            cb(err, result[0].jsondata);
        });
    }
    Projects.remoteMethod(
        'getProjectData', {
            returns: [{
                type: 'string',
                required: true,
                root: true
            }],
            http: {
                verb: 'get'
            }
        }
    );
};

我已经安装了 loopback-connector-postgresql 并生成了模型，但是当我尝试编写自定义 api 时出现错误。

Answer 1

在module.exports 声明之前

var app = require('../../server/server.js');

这是假设您在 common 文件夹中的模型目录中。

那么不要使用Projects.app.datasource，而是使用app.datasource