Recursive include Sequelize?

Question

I have category that can have child categories

And when I'm doing findAll I want to include all of those nested, but I don't know the depth.

var includeCondition = { 
                         include: [
                            { 
                               model: models.categories,
                               as:'subcategory', nested: true 
                            }]
                       };

models.categories.findAll(includeCondition)
        .then(function (categories) {
            resolve(categories);
        })
        .catch(function (err) {
            reject(err);
        })
});

The result brings me only one level nested include.

[  
   {  
      dataValues:{  

      },
      subcategory:{  
         model:{  
            dataValues:{  

            }
            // no subcategory here            
         }
      }
   }
]

Can I somehow make sequalize include those nested subcategories ?

Answer 1

This is ihoryam's answer adapted to ES6, using async/await, arrow functions () => and Sequelize ORM to fetch the data, and not using Lodash.

const getSubCategoriesRecursive = async (category) => {
  let subCategories = await models.category.findAll({
      where: {
          parentId: category.id
      },
      raw : true
  });

  if (subCategories.length > 0) {
      const promises = [];
      subCategories.forEach(category => {
          promises.push(getSubCategoriesRecursive(category));
      });
      category['subCategories'] = await Promise.all(promises);
  }
  else category['subCategories'] = []; 
  return category;
};

Async functions returning promises, you do not need to precise return new promise(...)

Answer 2

There are few solutions if found for this first one is more complicated but will give better performance:

This one is about implementing hierarchical data structure in MySQL I like the guide here

http://mikehillyer.com/articles/managing-hierarchical-data-in-mysql/

The one that is named The Nested Set Model.

The second solution that I actually implemented by myself is recursive expanding, this one uses lots of mysql requests and I believe can be improved, but it's a fast one and works well. The thing is to use for each category function like this

var expandSubcategories = function (category) {
    return new promise(function (resolve, reject) {
        category.getSubcategories().then(function (subcategories) {
            //if has subcategories expand recursively inner subcategories
            if (subcategories && subcategories.length > 0) {
                var expandPromises = [];
                _.each(subcategories, function (subcategory) {
                    expandPromises.push(expandSubcategories(subcategory));
                });

                promise.all(expandPromises).then(function (expandedCategories) {
                    category.subcategories = [];

                    _.each(expandedCategories, function (expandedCategory) {
                        category.subcategories.push(expandedCategory);
                    }, this);


                    //return self with expanded inner
                    resolve(category);
                });

            } else {
                //if has no subcategories return self
                resolve(category);
            }
        });
    });
};

So it's going through the categories and expanding them recursively.

Maybe this will help someone as well.