Sequelize.js foreign key

Question

When using Sequelize.js, the following code doesn't add any foreign key on tables.

var MainDashboard = sequelize.define('main_dashboard', {
  title: Sequelize.STRING
}, {
  freezeTableName: true
})

MainClient.hasOne(MainDashboard, { foreignKey: 'idClient' })
MainDashboard.hasOne(MainClient, { foreignKey: 'clientId' })

sequelize.sync({ force: true })

Is there any way to force Sequelize.js to add these foreign key constraints?

Solution 1

Before I had the same problem, and solved when I understood the functioning of settings Sequelize.

Straight to the point!

Suppose we have two objects: Person and Father

var Person = sequelize.define('Person', {

        name: Sequelize.STRING
});

var Father = sequelize.define('Father', {

        age: Sequelize.STRING,
        //The magic start here
        personId: {
              type: Sequelize.INTEGER,
              references: 'persons', // <<< Note, its table's name, not object name
              referencesKey: 'id' // <<< Note, its a column name
        }
});

Person.hasMany(Father); // Set one to many relationship

Maybe it helps you

Edit:

You can read this to understand better:

http://docs.sequelizejs.com/manual/tutorial/associations.html#foreign-keys

Solution 2

For Sequelize 4 this has been updated to the following:

const Father = sequelize.define('Father', {
        name: Sequelize.STRING
});

const Child = sequelize.define('Child', {
    age: Sequelize.STRING,
    fatherId: {
       type: Sequelize.INTEGER,
       references: {
          model: 'fathers', // 'fathers' refers to table name
          key: 'id', // 'id' refers to column name in fathers table
       }
    }
});

Father.hasMany(Child); // Set one to many relationship

Edit: You can read more on associations at https://sequelize.org/master/manual/assocs.html

Solution 3

You need to add foreignKeyConstraint: true

Try:

MainClient.hasOne(MainDashboard, { foreignKey: 'idClient', foreignKeyConstraint: true })

Solution 4

I just tried to run your code, and the rows seem to be created fine:

CREATE TABLE IF NOT EXISTS `main_dashboard` (`title` VARCHAR(255), `id` INTEGER NOT NULL auto_increment , `idClient` INTEGER, PRIMARY KEY (`id`)) ENGINE=InnoDB;
CREATE TABLE IF NOT EXISTS `main_client` (`id` INTEGER NOT NULL auto_increment,  `clientId` INTEGER, PRIMARY KEY (`id`)) ENGINE=InnoDB;

clientId is added to main_client, and idClient is added to main_dashboard

It seems you have slightly confused what the hasOne method does. Each time you call hasOne an association is created, so your code effectively associates the two tables twice. The method you are looking for is belongsTo

If you want each client to have one dashboard, the code would be the following:

MainClient.hasOne(MainDashboard, { foreignKey: 'clientId' })
MainDashboard.belongsTo(MainClient, { foreignKey: 'clientId' })

This creates a clientId field on the main_dashboard table, which relates to the id field of the main_client table

In short belongsTo adds the relation to the table that you are calling the method on, hasOne adds it on the table that is given as argument.

Solution 5

It's amazingly simple.

const MainDashboard = this.sequelize.define('main_dashboard', {/* attributes */}),
      MainClient    = this.sequelize.define('main_client', {/* attributes */});

MainDashboard.belongsTo(MainClient, { foreignKey: 'clientId' }); // Adds clientId to MainDashboard

It will link this as a foreign key and you may use it as an association. Let me know if I'm missing anything.

View more solutions

Comments

[Philippe Hebert]

The use of references and referencesKey is now deprecated => Utils deprecated Non-object references property found. Support for that will be removed in version 4. Expected { references: { model: "value", key: "key" } } instead of { references: "value", referencesKey: "key" }.

[Buksy]

this is not a good example, last command says that one Person has many Fathers which doesnt sound natural

[The Red Pea]

Is this still an option? I don't see the property foreignKeyConstraint in the API; only foreignKey. Oh! Maybe the property is now called simply: constraints? It is described as : "Should on update and on delete constraints be enabled on the foreign key. "

[Maksym Dudyk]

I guess, we must also write down foreign key in parent model, that is MainClient, like this: MainClient.hasMany(MainDashboard, { foreignKey: 'clientId' }); We must also add column 'clientId' manually to the MainDashboard migration file with an attribute: 'type: DataTypes.INTEGER'.