app2-api/modules/entities/entity.model.js

module.exports = function (sequelize, DataTypes) {
    const Entity = sequelize.define('Entity', {
        id: {
            type: DataTypes.UUID,
            defaultValue: DataTypes.UUIDV4,
            primaryKey: true,
        },
        name: {
            type: DataTypes.STRING,
            allowNull: false
        },
    }, {
        tableName: 'entities',
        freezeTableName: true,
        timestamps: true,
    });

    Entity.associate = function (models) {
        Entity.EntityTypes = Entity.belongsToMany(models.EntityType, { 
            through: models.EntityEntitiesTypes,
            foreignKey: 'entityId'
        });
        Entity.Users = Entity.hasMany(models.User, { foreignKey: 'entityId' });
        Entity.EventsReservations = Entity.hasMany(models.EventReservation, { foreignKey: 'entityId' });
    };
    return Entity;
};