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Sequelize M:N Association - "TypeError: Members.belongsToMany is not a function"

I have two tables in a MySQL schema, 'members' and 'events', which share a many-to-many relationship. I am attempting to model that relationship using Sequelize via a junction table containing a member_id and an event_id (which correspond to columns in the Members and Events tables respectively) and an event_date - the date when an event is attended by many members.
I am following the guidance in the Sequelize 'Advanced Associations' section (link), but am getting an error when my node.js server attempts to start, as follows:
Members.belongsToMany(models.Events, { through: 'member_events' })
^
TypeError: Members.belongsToMany is not a function
I'm really stuggling to understand what specifically this means and how I can address the issue. The following is my code for the three models in question:
memberEvents.js
module.exports = (sequelize, DataTypes) => {
const Members = require('../models/members')
const Events = require('../models/events')
const MemberEvents = sequelize.define(
"MemberEvents",
{
member_id: {
type: DataTypes.INTEGER,
allowNull: false,
primaryKey: true,
},
event_id: {
type: DataTypes.INTEGER,
allowNull: false,
primaryKey: true,
},
event_date: {
type: DataTypes.DATEONLY,
allowNull: false,
primaryKey: true,
},
},
{ tableName: "member_events" }
);
Members.belongsToMany(Events, { through: 'member_events' })
Events.belongsToMany(Members, { through: 'member_events' })
return MemberEvents;
};
Members.js
module.exports = (sequelize, DataTypes) => {
//Below creates the member table in the schema
const Members = sequelize.define(
"Members",
{
member_id: {
type: DataTypes.INTEGER,
autoIncrement: true,
allowNull: false,
primaryKey: true,
},
forename: {
type: DataTypes.STRING(35),
allowNull: false,
},
surname: {
type: DataTypes.STRING(35),
allowNull: false,
},
date_of_birth: {
type: DataTypes.DATEONLY,
allowNull: false,
},
address_1: {
type: DataTypes.STRING(35),
allowNull: false,
},
address_2: {
type: DataTypes.STRING(35),
},
address_3: {
type: DataTypes.STRING(35),
},
address_4: {
type: DataTypes.STRING(35),
},
address_5: {
type: DataTypes.STRING(35),
},
postcode: {
type: DataTypes.STRING(12),
allowNull: false,
},
directions: {
type: DataTypes.TEXT("long"),
},
mobile_phone: {
type: DataTypes.STRING(12),
},
email_address: {
type: DataTypes.STRING(255),
},
key_safe_code: {
type: DataTypes.STRING(8),
},
next_of_kin_name: {
type: DataTypes.STRING(70),
},
next_of_kin_phone: {
type: DataTypes.STRING(12),
},
next_of_kin_local: {
type: DataTypes.STRING(33),
},
next_of_kin_relationship: {
type: DataTypes.STRING(40),
},
doctor_name: {
type: DataTypes.STRING(35),
},
initial_medical_conditions: {
type: DataTypes.TEXT("long"),
},
deceased: {
type: DataTypes.DATEONLY,
},
normally_escorted: {
type: DataTypes.STRING(3),
},
blue_badge_holder: {
type: DataTypes.STRING(3),
},
medical_equipment: {
type: DataTypes.STRING,
},
},
{ tableName: "Member" }
);
return Members;
};
Events.js
module.exports = (sequelize, DataTypes) => {
//Below creates the event table in the schema
const Events = sequelize.define(
"Events",
{
event_id: {
type: DataTypes.INTEGER,
autoIncrement: true,
allowNull: false,
primaryKey: true,
},
event_name: {
type: DataTypes.STRING(70),
allowNull: false,
},
staff_id: {
type: DataTypes.INTEGER,
allowNull: false,
},
},
{ tableName: "Events" }
);
return Events;
};

When separating your Sequelize models into separate imports, use the associate function to access the models to make these associations. You also don't need to import the other models into each other.
Something along these lines should work:
TableA.js
module.exports = (sequelize, DataTypes) => {
const TableA = sequelize.define('table_a', {
foobar: DataTypes.STRING,
}, {});
TableA.associate = function(models) {
TableA.belongsTo(models.TableB, { through: 'table_c' });
};
return TableA;
};
TableB.js
module.exports = (sequelize, DataTypes) => {
const TableB = sequelize.define('table_b', {
fazbaz: DataTypes.STRING,
}, {});
TableB.associate = function(models) {
TableB.belongsTo(models.TableA, { through: 'table_c' });
};
return TableB;
};

How to use sequelize beforeCreate to autogenerate Id value?

I am tryiong to generate a BINARY(16) value for a model that Id.
I used the defaultValue parameter but ended up getting
duplicate key errors in mysql
.
So i found If I use beforeCreate then it would be uniqe every time but when Im doing the actual create im getting
Id can not be null errors
my model:
const utility = require('utils/utilities');
module.exports = function(sequelize, DataTypes) {
const weddings = sequelize.define(
'weddings', {
Id: {
primaryKey: true,
allowNull: false,
type: 'BINARY(16)',
},
Name: {
type: DataTypes.STRING(150),
allowNull: false,
comment: 'null',
},
HouseId: {
type: DataTypes.INTEGER(11),
allowNull: false,
comment: 'null',
references: {
model: 'house',
key: 'Id',
},
},
WDate: {
type: DataTypes.DATE,
allowNull: false,
comment: 'null',
},
Active: {
type: DataTypes.BOOLEAN,
allowNull: false,
comment: 'null',
},
},
{
hooks: {
beforeCreate() {
const generateValue = Buffer.from(utility.generateUID().replace('-', ''), 'hex');
weddings.Id = generateValue;
}
}
}, {
tableName: 'weddings',
}
);
return weddings;
};
error:
weddings.Id cannot be null
What am I missing?

You can use instance hook like this:
const utility = require('utils/utilities');
module.exports = function(sequelize, DataTypes) {
const weddings = sequelize.define(
'weddings', {
Id: {
primaryKey: true,
allowNull: false,
type: 'BINARY(16)',
},
Name: {
type: DataTypes.STRING(150),
allowNull: false,
comment: 'null',
},
HouseId: {
type: DataTypes.INTEGER(11),
allowNull: false,
comment: 'null',
references: {
model: 'house',
key: 'Id',
},
},
WDate: {
type: DataTypes.DATE,
allowNull: false,
comment: 'null',
},
Active: {
type: DataTypes.BOOLEAN,
allowNull: false,
comment: 'null',
},
},
{
}, {
tableName: 'weddings',
}
);
weddings.beforeCreate(async (data, options) => {
data.Id = await Buffer.from(utility.generateUID().replace('-', ''), 'hex');
});
return weddings;
};
If you want to emit hooks for each individual record, along with the bulk hooks you can pass individualHooks: true to the call.
table.update( req.body, {
where: where,
returning: true,
individualHooks: true
plain: true
})
create:
db.weddings.create({
...args,
}),
for other information you can read it at:
https://sequelize.org/v5/manual/hooks.html

Sequelize Seeding ARRAY(ENUM)

I cannot seem to figure out how to seed ARRAY(ENUM) using Sequelize. When I am registering a user via my app, I can create a new user fine, but when I am using the queryInterface.bulkInsert in a seed file, I am getting:
ERROR: column "roles" is of type "enum_Users_roles"[] but expression is of type text[]
here is my code:
return queryInterface.bulkInsert('Users', [
{
email: faker.internet.email(),
roles: ['user'],
password: "hash",
public_id: faker.random.uuid(),
created_at: new Date(),
updated_at: new Date()
}
]);
and here is my migration file for the user:
return queryInterface.createTable('Users', {
id: {
allowNull: false,
autoIncrement: true,
primaryKey: true,
type: Sequelize.INTEGER
},
email: {
type: Sequelize.STRING,
allowNull: false
},
password: {
type: Sequelize.STRING,
allowNull: false
},
roles: {
type: Sequelize.ARRAY(Sequelize.ENUM({
values: ['user', 'setter', 'admin']
})),
allowNull: false
},
public_id: {
type: Sequelize.UUID,
defaultValue: Sequelize.UUIDV4,
allowNull: false
},
created_at: {
allowNull: false,
type: Sequelize.DATE
},
updated_at: {
allowNull: false,
type: Sequelize.DATE
}
})
I am just assuming that I am doing it wrong, but I cannot find any documentation on how to do it correctly. If anyone can help and explain (teach a man to fish), I would appreciate it.

Someone answered on github here
This is their answer which worked for me (and I greatly appreciate)
You can use this code
class Item extends Sequelize.Model { }
Item.init({
name: { type: DataTypes.STRING },
values: {
type: DataTypes.ARRAY(DataTypes.ENUM({
values: ['a', 'b']
}))
}
}, {
sequelize,
timestamps: true
})
sequelize.sync({ force: true }).then(async () => {
await sequelize.queryInterface.bulkInsert('Items', [
{
name: 'xyz',
values: sequelize.literal(`ARRAY['a']::"enum_Items_values"[]`),
createdAt: new Date(),
updatedAt: new Date()
}
]);
});
Executing (default): INSERT INTO "Items" ("name","values","createdAt","updatedAt") VAL
[1]: https://github.com/sequelize/sequelize/issues/11541#issuecomment-542791562
Obviously you'll want to change the array values and enum values. For example, mine would be
ARRAY['user']::"enum_Users_values"[]

Sequelize request error SequelizeEagerLoadingError

I’m new with sequelize I’m trying to make a request with associate tables
I have a first model called Experience
module.exports = function (sequelize, DataTypes) {
const Experience = sequelize.define('experience', {
internalId: {
type: DataTypes.BIGINT,
unique: true,
allowNull: false,
},
label: {
type: DataTypes.STRING,
unique: false,
allowNull: false,
},
picture: {
type: DataTypes.TEXT,
unique: false,
allowNull: true,
},
type: {
type: DataTypes.STRING,
validate: {
isIn: {
args: [[
'generic',
'specific',
]],
msg: 'Must be a valid type',
},
},
unique: false,
allowNull: true,
},
author: {
type: DataTypes.STRING,
unique: false,
allowNull: true,
defaultValue: 'import',
},
isActive: {
type: DataTypes.BOOLEAN,
defaultValue: true,
},
});
Experience.associate = (models) => {
Experience.belongsToMany(models.Tag, {
as: 'Tags',
through: models.ExperienceTag,
});
};
return Experience;
};
a second called Tags
module.exports = function (sequelize, DataTypes) {
const Tag = sequelize.define('tag', {
internalId: {
type: DataTypes.STRING,
unique: true,
allowNull: false,
},
name: {
type: DataTypes.STRING,
unique: false,
allowNull: false,
},
author: {
type: DataTypes.STRING,
unique: false,
allowNull: true,
defaultValue: 'import',
},
isActive: {
type: DataTypes.BOOLEAN,
defaultValue: true,
},
});
Tag.associate = (models) => {
Tag.belongsToMany(models.Experience, {
as: 'Experiences',
through: models.ExperienceTag,
});
};
return Tag;
};
The association table name was ExperienceTags
I would like get all the Experiencewho have a tagId = 44
This is my request:
Experience.findAll({
include: [{
model: ExperienceTag,
where: { tagId: 44 },
}],
})
.then((results) => {
winston.warn(JSON.stringify(results, null, 2));
res.status(200)
.send(results);
})
.catch(error => res.status(500)
.send({ error: error.toString() }));
But when I execute it I have an error like:
{
"error": "SequelizeEagerLoadingError: experienceTag is not associated to experience!"
}

I think you like to include Tag rather than ExperienceTag, the following example may help you
Experience.findAll({
include: [{
model: Tag, //model name which you want to include
as: 'Tags', // you have to pass alias as you used while defining
where: { tagId: 44 },
}],
})

I think , you need to add as: 'Experiences' , in your include as you have defined association with alias
Change this
Experience.findAll({
include: [{
model: ExperienceTag,
where: { tagId: 44 },
}],
})
With
Experience.findAll({
include: [{
model: ExperienceTag,
as: 'Experiences', // <---- HERE
where: { tagId: 44 },
}],
})

Returning parent attributes via sequelize

I am working on a NodeJs application using sequelize as an ORM with exciting database , so I had to use sequelize model generator in order to generate the models for my application.
Here's an example of the generation output:
Category.js
module.exports = function(sequelize, DataTypes) {
return sequelize.define('category', {
id: {
type: DataTypes.STRING(128),
allowNull: false,
primaryKey: true,
field: 'id'
},
name: {
type: DataTypes.TEXT,
allowNull: true,
field: 'name'
}
}, {
tableName: 'category'
});
};
Product.js
module.exports = function(sequelize, DataTypes) {
return sequelize.define('product', {
id: {
type: DataTypes.STRING(128),
allowNull: false,
primaryKey: true,
field: 'id'
},
category: {
type: DataTypes.STRING(128),
allowNull: false,
references: {
model: 'category',
key: 'id'
},
field: 'category'
},
name: {
type: DataTypes.TEXT,
allowNull: true,
field: 'name'
}
}, {
tableName: 'product'
});
};
and then inside my controller I have this query :
models.product.findOne({
where: {
id: req.body.id
}
}).then(function (obj) {
//return the product data
console.log(product.category) //works
console.log(product.category.name) //return undefined
});
The question is how can I access to the parent table attribute via the same query findOne ? Is there something like or equivalent to product.category.id ?

if you have associated both the models... then try this
module.exports = function(sequelize, DataTypes) {
return sequelize.define('product', {
id: {
type: DataTypes.STRING(128),
allowNull: false,
primaryKey: true,
field: 'id'
},
category_id: {
type: DataTypes.STRING(128),
allowNull: false,
references: {
model: 'category',
key: 'id'
},
field: 'category'
},
name: {
type: DataTypes.TEXT,
allowNull: true,
field: 'name'
}
}, {
tableName: 'product'
});
}
models.product.findOne({
where: {
id: req.body.id
},
include: [{
model: category,
required: false
}]
}).then(function (obj) {
//return the product data
console.log(product.category) //works
console.log(product.category.name) //return undefined
});
Associate like this
product.hasMany(db.category, {
foreignKey: 'category_id',
onDelete: 'cascade'
});
category.belongsTo(db.product, {
foreignKey: 'category_id',
targetKey: 'id',
constraints: true
});