通过自定义列序列化多对多订单关联表

Question

i am building a desktop app with electron and MySQL

1- how to order association table results by custom column in many to many association

 //Company model
    const Company = sequelize.define("Company", {
       name: {
       type: DataTypes.STRING,
       allowNull: false,
      },    
    });
    
    //Branch Model
    const Branch = sequelize.define("Branch", {
        name: {
        type: DataTypes.STRING,
        allowNull: false,
        },
        description: {
        type: DataTypes.STRING,
       },
    });

    //Associations
    //join table
    const CompanyBranch = sequelize.define("CompanyBranch",
    {
    order: {
      type: DataTypes.INTEGER,
    },
    });

    Branch.belongsToMany(Company, {
    through: CompanyBranch,
    as: "Branches",
    });

    Company.belongsToMany(Branch, {
    through: CompanyBranch,
    });

2- how to map results to the correct shape instead of having nested object.

NB: in JavaScript Branch.order //=> undefined

My query

 //query
  const companies = await Company.findAll({include: [Branch]})
  //result
  {
   //company attrs
   Branches: [
   {id: 1, name: "branch 1", description: null, 
   CompanyBranch: { CompanyId: 1, ActivityId: 1,  BranchId: 1, order: 1}]
   }

The result i want to have

 {
   //company attrs
   Branches: [
   {id: 1, name: "branch 1", description: null,  order: 1}]
   }


  

Answer 1

You can try to use the attributes option to include the CompanyBranch.order field as the order field of Branch:

const companies = await Company.findAll({
  include: [
  {
     model: Branch,
     attributes: ['id', 'name', 'description', [Sequelize.col('CompanyBranch.order'), 'order']]
  }
]})

Upd. If you wish to order by CompanyBranch.order then it's better to add associations from Company to CompanyBranch and from CompanyBranch to Branch ( hasMany and belongsTo respectively) and use them like this:

Company.hasMany(CompanyBranch);
CompanyBranch.belongsTo(Branch);
...
const companies = await Company.findAll({
  include: [
  {
     model: CompanyBranch,
     attributes: ['order'],
     include: [{
       model: Branch,
       attributes: ['id', 'name', 'description'] 
     },
  }],
  order: [['CompanyBranch', 'order', 'ASC']]
})

That way you can also indicate what fields you wish to get from CompanyBranch and from Branch even on the CompanyBranch level using notation like ['AssociationName.field', 'alias']

Answer 2

the solution is to use Sequelize literal to order by custom join table column

const companies = await Company.findAll({
include: [Branch],
order: [[Sequelize.literal("`Branches->CompanyBranch`.`order`"), "ASC"]]
})