Relationships

Link schemas together to build complex, interconnected data structures without repeating yourself.

What are References?

In a real database, you don't store the full User object inside every Post. You store a reference (Foreign Key).

Mock66 allows you to do something similar, but better for mocking: Embedding. When you reference another schema, we inject the generated data of that schema directly into your response.

Schema A (User)

json

{
  "id": "user_123",
  "name": "Jane Doe"
}

Schema B (Post) embeds User

json

{
  "title": "My Post",
  "author": {
    "id": "user_123",
    "name": "Jane Doe"
  }
}

Creating a Relationship

You can turn any field into a reference using the Visual Builder.

Create the Source Schema: First, create the schema you want to reuse (e.g., "User") and save it.
Create the Parent Schema: Open a new schema (e.g., "Post").
Add a Field: Create a new field named author.
Change Type: Select the type dropdown and choose Ref.
Select Target: A new dropdown will appear showing your existing schemas. Select "User".

Relationship Types

One-to-One (Single Object)

Embeds a single object.

Example: Product has one Manufacturer.

One-to-Many (Array of Objects)

Embeds a list of objects.

To do this, create an Array field first, then select a schema that will be used to populate the array.

Large Children Array Protection: In order to prevent performance issues, Mock66 limits the maximum number of items in an embedded array to 50 items.

Recursion Depth

Infinite Loop Protection: If Schema A references Schema B, and Schema B references Schema A back, you could theoretically generate infinite data.

To prevent your browser or our servers from crashing, Mock66 enforces a hard limit of 3 levels of nesting.

1User (Level 1)

2↳ Posts (Level 2)

3↳ Comments (Level 3)

X↳ Author (Level 4 - Returns Null)

When the limit is reached, the generator will simply return null for that field.

Relationships

Link schemas together to build complex, interconnected data structures without repeating yourself.

What are References?

In a real database, you don't store the full User object inside every Post. You store a reference (Foreign Key).

Mock66 allows you to do something similar, but better for mocking: Embedding. When you reference another schema, we inject the generated data of that schema directly into your response.

Schema A (User)

json

{
  "id": "user_123",
  "name": "Jane Doe"
}

Schema B (Post) embeds User

json

{
  "title": "My Post",
  "author": {
    "id": "user_123",
    "name": "Jane Doe"
  }
}

Creating a Relationship

You can turn any field into a reference using the Visual Builder.

Create the Source Schema: First, create the schema you want to reuse (e.g., "User") and save it.
Create the Parent Schema: Open a new schema (e.g., "Post").
Add a Field: Create a new field named author.
Change Type: Select the type dropdown and choose Ref.
Select Target: A new dropdown will appear showing your existing schemas. Select "User".

Relationship Types

One-to-One (Single Object)

Embeds a single object.

Example: Product has one Manufacturer.

One-to-Many (Array of Objects)

Embeds a list of objects.

To do this, create an Array field first, then select a schema that will be used to populate the array.

Large Children Array Protection: In order to prevent performance issues, Mock66 limits the maximum number of items in an embedded array to 50 items.

Recursion Depth

Infinite Loop Protection: If Schema A references Schema B, and Schema B references Schema A back, you could theoretically generate infinite data.

To prevent your browser or our servers from crashing, Mock66 enforces a hard limit of 3 levels of nesting.

1User (Level 1)

2↳ Posts (Level 2)

3↳ Comments (Level 3)

X↳ Author (Level 4 - Returns Null)

When the limit is reached, the generator will simply return null for that field.