CODEWITHSUNDEEP
node.jsbookshelf.jsknex.js
Mitchell Loeppky
Mitchell Loeppky

Reputation: 149

Bookshelf.js, query on related table

I have a model similar to the following:

var ScholarlyPaper = Bookshelf.Model.extend({

  tableName: 'papers',

  paragraphs: function() {
    return this.hasMany(Paragraph).through(Section);
  },

  sections: function() {
    return this.hasMany(Section);
  }

});

var Section = Bookshelf.Model.extend({

  tableName: 'sections',

  paragraphs: function() {
    return this.hasMany(Paragraph);
  }

  scholarlyPaper: function() {
    return this.belongsTo(ScholarlyPaper);
  }

});

var Paragraph = Bookshelf.Model.extend({

  tableName: 'paragraphs',

  section: function() {
    return this.belongsTo(Section);
  },

  scholarlyPaper: function() {
    return this.belongsTo(ScholarlyPaper).through(Section);
  },

  author: function() {
    return this.belongsTo(Author);
  }

});

var Author = Bookshelf.Model.extend({

  tableName: 'authors',

  paragraphs: function() {
    return this.hasMany(Paragraph);
  }

});

Using Bookshelf.js, given a scholarlyPaper id and author id, how can I get all of the sections in the paper that the author did not write a single paragraph in?

The particular challenge I am facing is that there is no way that I am aware of to add a where clause on a related table (e.g 'where paragraphs.author_id != author_id).

Upvotes: 6

Views: 10057

Answers (3)

black21jack
black21jack

Reputation: 71

Check out the bookshelf-eloquent extension. The whereHas() and with() functions are probably what you are looking for. Your function would look something like this:

async function(authorId, paperId) {
    return await ScholarlyPaper.where('id', paperId)
        .with('sections', (q) {
            // Filter out sections in the paper that the author did not write a single paragraph in.
            q.whereHas('paragraphs', (q) => {
                q.where('author_id', authorId);
            }, '<=', 0);
        }).first();
}

Upvotes: 1

Mitchell Loeppky
Mitchell Loeppky

Reputation: 149

function(authorId, paperId, success, failure) {
  new ScholarlyPaper({id: paperId}).load({sections: function(qb) {
    qb.whereNotExists(function() {
      this.from('paragraph')
        .whereRaw('paragraph.section = section.id')
        .where('paragraph.author_id', '=', authorId);
    });
  }}).then(function(paper) {
    success(paper.related('section'));
  }, failure);
};

Upvotes: 1

tgriesser
tgriesser

Reputation: 2808

Does this work?

new ScholarlyPaper({id: 1}).load({paragraphs: function(qb) {
  qb.where('paragraphs.author_id', '!=', author_id);
}}).then(function(paper) {
  console.log(JSON.stringify(paper.related('paragraphs')));
});

Upvotes: 2

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