使用关联对 n:m 相关对象进行序列化错误

Question

I am using nodeJS, express (4.17.1), sequelize (5.21.4) and mysql (mysql2 v2.1.0) for a current project.

In my database I have three tables Filter, Element and FilterElement. If I query data from database from Filter or Element table separatly I get the result of objects with data. If I want to use "connecting" table FilterElement I get this error {"name":"SequelizeEagerLoadingError"}

EagerLoadingError [SequelizeEagerLoadingError]: filter_element is not associated to filters_new!

What is wrong with my code? These are my sequelize objects codes.

Filter.js

 const Sequelize = require('sequelize'); const db = require('../config/database'); const Filter = db.define('filters_new', { Model:{ type: Sequelize.STRING, primaryKey: true, allowNull: false } }, { timestamps: false, freezeTableName: true } ); Filter.associate = function(models) { Filter.belongsToMany(models.Element, { through: models.FilterElement, as: 'filter', foreignKey: 'FilterHousingModel' }); }; module.exports = Filter;

Element.js

 const Sequelize = require('sequelize'); const db = require('../config/database'); const Element = db.define('filter_element', { idfilter_element:{ type: Sequelize.INTEGER, primaryKey: true, allowNull: false }, ElementName:{ type: Sequelize.STRING, } }, { timestamps: false, freezeTableName: true } ); Element.associate = function(models) { Element.belongsToMany(models.Filter, { through: models.FilterElement, as: 'element', foreignKey: 'FilterElementId' }); }; module.exports = Element;

FilterElemnt.js

 const Sequelize = require('sequelize'); const db = require('../config/database'); const FilterElement = db.define('filters_new', { idfilter_filterelement:{ type: Sequelize.STRING, primaryKey: true, allowNull: false, autoincrement: true }, FilterHousingModel: { type: Sequelize.STRING }, FilterElementId: { type: Sequelize.INTEGER } }, { timestamps: false, freezeTableName: true } ); module.exports = FilterElement;

If I call this function, I do get the desired result of data from database.

 listFiltersOnly(req, res) { return filter.findAll() .then((filters) => { res.status(200).send(filters); }) .catch(err => { console.log(err); res.status(400).send(err); }); }

then if I call function list I get the error mentioned up EagerLoadingError

 list(req, res) { return filter.findAll({ include: [{ model: element, as: 'element' }], }) .then((filters) => { console.log(filters); res.status(200).send(filters); }) .catch(err => { console.log(err); res.status(400).send(err); }); }

Looking for some suggjestions where might be the problem?

Answer 1

@RatulSharker I removed the asociation from the model and added it where the models are implemented in the controller and now I do get some results.

 Filter.belongsToMany(FilterElement, { through: FilterFilterElement, foreignKey: 'FilterHousingModel' }); FilterElement.belongsToMany(Filter, { through: FilterFilterElement, foreignKey: 'FilterElementId' });

Thank you @Ratul Sharker