Zero to Many relationships

[Icaro_Targino]

How can I do a zero-to-many relationship to my model?
Does anyone have seen how to make it before?

[chiawh]

Any chance we can annotate zero relationships?

[Thi_Nguyen]

Update March 2025: This feature was recently released. You can now test it by defining a relationship with and without nullability for the foreign key. For instance:

Table follows {
  following_user_id int [ref: > users.id] // optional relationship
  followed_user_id int [ref: > users.id, null] // optional relationship
}

Table posts {
  id int [pk]
  user_id int [ref: > users.id, not null] // mandatory relationship
}

Table users { 
  id int [pk]
}

The outcome will be as follows:

Upgrade for Database Relationships: Zero-to-One/Many Relationships, Colors and more!

Valentine’s Day taught us relationships can be rock-solid or a little… optional —and your database is no different! Our latest update lets you define optional or mandatory relationships, customize their colors, and add names to make your diagrams clearer and more meaningful. Optional or Mandatory Relationships (free plan) Using the nullable constraint on the foreign key, we can now automatically determine whether a relationship is optional (zero-to-one/many) or mandatory (one-to-o…

[huydna]

Optional refs have been fully supported with a syntax to denote in dbml version 9.0.0. You can check the doc here: DBML Syntax — Core Database Markup | DBML

A glance of the syntax:

Table users {
  id int [pk]
}

Table profiles {
  id int [pk]
  uid int [unique]
}

Ref: users.id ?-? profiles.id // users can have a profile or not, a profile can belong to a user or not