Typescript example of M:N relationship (belongsToMany) with through table attributes

[hburrows]

Issue Description

Examples of using Typescript with many-to-many relationships (i.e. belongsToMany <-> belongsToMany)

What was unclear/insufficient/not covered in the documentation

Only simple relationship examples exist: i.e hasMany

Additional context

I've looked through the type definitions and tests and I'm coming up empty-handed.

Simple example:

class Account extends Model { }

class User extends Model {
  public addAccount!: ????
}

User.belongsToMany(Account, { through: AccountUser });
Account.belongsToMany(User, { through: AccountUser });

userInst.addAccount(accountInst, { through: { role: 'owner' } })

How do I declare the addAccount method of class User? My through table (AccountUser) has a single attribute (role). I've looked through the code (i.e. associations/belongs-to-many.d.ts) but I'm stumped. It appears that BelongsToManyAddAssociationMixin takes 3 arguments but when I express something like:

public addAccount!: BelongsToManyAddAssociationMixin<Account, string, { role: string }>;

it complains with Generic type 'BelongsToManyAddAssociationMixin' requires 2 type argument(s)

Some help and guidance would be greatly appreciated. I'd be happy to contribute to the Typescript documentation page to cover this use case.

Is this issue dialect-specific?

• No. This issue is relevant to Sequelize as a whole.
• Yes. This issue only applies to the following dialect(s): Typescript
• I don't know.

Would you be willing to resolve this issue by submitting a Pull Request?

• Yes, I have the time and I know how to start.
• Yes, I have the time but I don't know how to start, I would need guidance.
• No, I don't have the time, although I believe I could do it if I had the time...
• No, I don't have the time and I wouldn't even know how to start.

[papb]

Hello!

userInst.addAccount(accountInst, { throught: { role: 'owner' } })

There is a typo here, throught -> through

[hburrows]

@papb Thanks for pointing that out. I fixed it. I finally figured out how to make it work. More examples would be good, however.

[papb]

I finally figured out how to make it work.

Nice!!

More examples would be good, however.

I agree 😬 Would you be willing to post how did you finally make it work?

[Crodaycat]

Hello, can somebody please show an example project to reach M:N realtionships.

Thanks.

[Reinoptland]

Hey @Crodaycat & others

I am also working on my first Sequelize / Typescript selfstudy project. I found this example to be pretty useful (though it is from 2 years ago)

https://github.com/ahmerb/typescript-sequelize-example

[github-actions]

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[Taqiarzoo]

there is very less documentation for sequlize typescript
i spend hours to figure out how to disable unique constrain on through table,
here is the code snippet

Design.belongsToMany(File, { through: { model: FileUsage, unique: false }, as: 'design_files', foreignKey: Design_.DESIGNID, otherKey: GlobalFile.FILEID })

File.belongsToMany(Design, { through: { model: FileUsage, unique: false }, as: 'design_files', foreignKey: GlobalFile.FILEID, otherKey: Design_.DESIGNID })

but i still don't know how to do the same with this syntax

@BelongsToMany(() => Design, { through: () => RelatedDesign, as: 'design' })