本棚のwithRelatedなって「未定義のプロパティを読み取ることができません 『のtoString』」を使用して

Question

私はこのようになります本棚モデルのセット持っている：

：knex、私のセットアップそうのようなスキーマを使用して

const User = bookshelf.Model.extend({ 
    tableName: 'users', 
    hasTimestamps: true, 
    posts: function() { 
    return this.hasMany(Posts); 
    }, 
}); 

const Posts = bookshelf.Model.extend({ 
    tableName: 'posts', 
    hasTimestamps: true, 
    author: function() { 
    return this.belongsTo(User); 
    }, 
}); 

を私は、その後のポストを取得するために設計されたサーバーのルートに次のように実行します

Promise.all([ 
    knex.schema.createTableIfNotExists('users', (tbl) => { 
     tbl.increments('id').primary(); 
     tbl.string('name'); 
     tbl.string('username'); 
     tbl.string('email'); 
     tbl.timestamps(); 
    }), 
    knex.schema.createTableIfNotExists('posts', (tbl) => { 
     tbl.increments(); 
     tbl.string('title'); 
     tbl.string('body'); 
     tbl.integer('author').references('users.id'); 
     tbl.timestamps(); 
    }) 
]); 

：

app.get('/post/:id', (req,res) => { 
    if(_.isUndefined(req.params.id)) 
    return; 
    Posts 
    .forge({id: req.params.id}) 
    .fetch({withRelated: 'author'}) 
    .then((post) => { 
     res.send(post); 
    }); 
}); 

I次のエラーが表示されます。

Unhandled rejection TypeError: Cannot read property 'toString' of undefined 
    at Object.prepareValue (/Users/ethan/Flatiron/node/unit4/node-js-intro-to-bookshelf/node_modules/knex/lib/dialects/postgres/utils.js:48:13) 
    at /Users/ethan/Flatiron/node/unit4/node-js-intro-to-bookshelf/node_modules/knex/lib/dialects/postgres/index.js:61:20 
    at arrayMap (/Users/ethan/Flatiron/node/unit4/node-js-intro-to-bookshelf/node_modules/knex/node_modules/lodash/lodash.js:595:23) 
    at map (/Users/ethan/Flatiron/node/unit4/node-js-intro-to-bookshelf/node_modules/knex/node_modules/lodash/lodash.js:8778:14) 
    at Client.prepBindings (/Users/ethan/Flatiron/node/unit4/node-js-intro-to-bookshelf/node_modules/knex/lib/dialects/postgres/index.js:60:28) 
    at QueryCompiler_PG.toSQL (/Users/ethan/Flatiron/node/unit4/node-js-intro-to-bookshelf/node_modules/knex/lib/query/compiler.js:49:37) 
    at QueryBuilder.toSQL (/Users/ethan/Flatiron/node/unit4/node-js-intro-to-bookshelf/node_modules/knex/lib/query/builder.js:40:44) 
    at /Users/ethan/Flatiron/node/unit4/node-js-intro-to-bookshelf/node_modules/knex/lib/runner.js:34:32 
    at tryCatcher (/Users/ethan/Flatiron/node/unit4/node-js-intro-to-bookshelf/node_modules/knex/node_modules/bluebird/js/release/util.js:16:23) 
    at /Users/ethan/Flatiron/node/unit4/node-js-intro-to-bookshelf/node_modules/knex/node_modules/bluebird/js/release/using.js:184:26 
    at tryCatcher (/Users/ethan/Flatiron/node/unit4/node-js-intro-to-bookshelf/node_modules/knex/node_modules/bluebird/js/release/util.js:16:23) 
    at Promise._settlePromiseFromHandler (/Users/ethan/Flatiron/node/unit4/node-js-intro-to-bookshelf/node_modules/knex/node_modules/bluebird/js/release/promise.js:502:31) 
    at Promise._settlePromise (/Users/ethan/Flatiron/node/unit4/node-js-intro-to-bookshelf/node_modules/knex/node_modules/bluebird/js/release/promise.js:559:18) 
    at Promise._settlePromise0 (/Users/ethan/Flatiron/node/unit4/node-js-intro-to-bookshelf/node_modules/knex/node_modules/bluebird/js/release/promise.js:604:10) 
    at Promise._settlePromises (/Users/ethan/Flatiron/node/unit4/node-js-intro-to-bookshelf/node_modules/knex/node_modules/bluebird/js/release/promise.js:683:18) 
    at Promise._fulfill (/Users/ethan/Flatiron/node/unit4/node-js-intro-to-bookshelf/node_modules/knex/node_modules/bluebird/js/release/promise.js:628:18) 
    at PromiseArray._resolve (/Users/ethan/Flatiron/node/unit4/node-js-intro-to-bookshelf/node_modules/knex/node_modules/bluebird/js/release/promise_array.js:125:19) 
    at PromiseArray._promiseFulfilled (/Users/ethan/Flatiron/node/unit4/node-js-intro-to-bookshelf/node_modules/knex/node_modules/bluebird/js/release/promise_array.js:143:14) 
    at Promise._settlePromise (/Users/ethan/Flatiron/node/unit4/node-js-intro-to-bookshelf/node_modules/knex/node_modules/bluebird/js/release/promise.js:564:26) 
    at Promise._settlePromise0 (/Users/ethan/Flatiron/node/unit4/node-js-intro-to-bookshelf/node_modules/knex/node_modules/bluebird/js/release/promise.js:604:10) 
    at Promise._settlePromises (/Users/ethan/Flatiron/node/unit4/node-js-intro-to-bookshelf/node_modules/knex/node_modules/bluebird/js/release/promise.js:683:18) 
    at Async._drainQueue (/Users/ethan/Flatiron/node/unit4/node-js-intro-to-bookshelf/node_modules/knex/node_modules/bluebird/js/release/async.js:138:16) 
    at Async._drainQueues (/Users/ethan/Flatiron/node/unit4/node-js-intro-to-bookshelf/node_modules/knex/node_modules/bluebird/js/release/async.js:148:10) 
    at Immediate.Async.drainQueues [as _onImmediate] (/Users/ethan/Flatiron/node/unit4/node-js-intro-to-bookshelf/node_modules/knex/node_modules/bluebird/js/release/async.js:17:14) 
    at tryOnImmediate (timers.js:534:15) 
    at processImmediate [as _immediateCallback] (timers.js:514:5) 

ここで何が起こっているのか分かりませんか？

Answer 1

非標準の外部キー名（author_idの代わりにauthor - http://bookshelfjs.org/#Model-instance-belongsToを参照）を使用しています。だからあなたのモデルの関係は次のように固定されるべきです：

const User = bookshelf.Model.extend({ 
    tableName: 'users', 
    hasTimestamps: true, 
    posts: function() { 
    return this.hasMany(Posts, 'author'); 
    }, 
}); 

const Posts = bookshelf.Model.extend({ 
    tableName: 'posts', 
    hasTimestamps: true, 
    author: function() { 
    return this.belongsTo(User, 'author'); 
    }, 
});