Sequence Generator

Generates sequential (auto-incrementing) numbers.

Basic Usage

{
  "id": {"gen": "sequence"}
}

Output: 0, 1, 2, 3, 4, ... (starting from 0, incrementing by 1)

Options

Option	Type	Default	Description
start	integer	0	Starting value
increment	integer	1	Increment step

Examples

Starting from 1

{
  "id": {"gen": "sequence", "start": 1, "increment": 1}
}

Output: 1, 2, 3, 4, 5, ...

Custom Increment

{
  "id": {"gen": "sequence", "start": 100, "increment": 10}
}

Output: 100, 110, 120, 130, 140, ...

Even Numbers

{
  "evenNumber": {"gen": "sequence", "start": 0, "increment": 2}
}

Output: 0, 2, 4, 6, 8, ...

Odd Numbers

{
  "oddNumber": {"gen": "sequence", "start": 1, "increment": 2}
}

Output: 1, 3, 5, 7, 9, ...

Independent Sequences

Each field using sequence has its own independent counter:

{
  "users": {
    "count": 5,
    "item": {
      "userId": {"gen": "sequence", "start": 1, "increment": 1},
      "accountId": {"gen": "sequence", "start": 1000, "increment": 1}
    }
  }
}

Output:

[
  {"userId": 1, "accountId": 1000},
  {"userId": 2, "accountId": 1001},
  {"userId": 3, "accountId": 1002},
  {"userId": 4, "accountId": 1003},
  {"userId": 5, "accountId": 1004}
]

Common Patterns

Primary Keys

{
  "users": {
    "count": 100,
    "item": {
      "id": {"gen": "sequence", "start": 1, "increment": 1},
      "name": {"gen": "name.fullName"},
      "email": {"gen": "internet.emailAddress"}
    }
  }
}

Order Numbers

{
  "orders": {
    "count": 500,
    "item": {
      "orderNumber": {"gen": "sequence", "start": 10000, "increment": 1},
      "customerId": {"ref": "customers[*].id"},
      "total": {"gen": "float", "min": 10, "max": 1000, "decimals": 2}
    }
  }
}

Invoice Numbers

{
  "invoices": {
    "count": 200,
    "item": {
      "invoiceNumber": {"gen": "sequence", "start": 2024001, "increment": 1},
      "date": {"gen": "date"},
      "amount": {"gen": "float", "min": 100, "max": 10000, "decimals": 2}
    }
  }
}

Version Numbers

{
  "releases": {
    "count": 20,
    "item": {
      "version": {"gen": "sequence", "start": 1, "increment": 1},
      "name": {"gen": "lorem.word"},
      "releaseDate": {"gen": "date"}
    }
  }
}

Time Series Data

{
  "measurements": {
    "count": 24,
    "item": {
      "hour": {"gen": "sequence", "start": 0, "increment": 1},
      "temperature": {"gen": "float", "min": 15.0, "max": 30.0, "decimals": 1},
      "humidity": {"gen": "number", "min": 30, "max": 80}
    }
  }
}

Pagination

{
  "pages": {
    "count": 50,
    "item": {
      "pageNumber": {"gen": "sequence", "start": 1, "increment": 1},
      "content": {"gen": "lorem.paragraph"}
    }
  }
}

With References

Sequence-generated IDs can be referenced:

{
  "categories": {
    "count": 5,
    "item": {
      "id": {"gen": "sequence", "start": 1, "increment": 1},
      "name": {"gen": "lorem.word"}
    }
  },
  "products": {
    "count": 50,
    "item": {
      "id": {"gen": "sequence", "start": 1, "increment": 1},
      "categoryId": {"ref": "categories[*].id"},
      "name": {"gen": "lorem.word"}
    }
  }
}

Comparison with UUID

Feature	Sequence	UUID
Format	Integer	String (36 chars)
Readability	High	Low
Sortability	Natural order	Random
Uniqueness	Within collection	Globally unique
Use Case	Numeric IDs, counters	Distributed systems

Use Sequence when:

• You need human-readable IDs
• You want natural ordering
• You're generating SQL for databases with auto-increment

Use UUID when:

• You need globally unique identifiers
• You're working with distributed systems
• You want to avoid ID collisions

Best Practices

1. Start from 1: Most databases use 1-based IDs
2. Use for Counters: Perfect for sequential counters
3. Independent Sequences: Each field gets its own sequence
4. Combine with References: Use sequence IDs in relationships
5. Consider UUID: Use UUID for distributed systems

Limitations

• Sequences are per-field, not per-collection
• Cannot share sequence state between fields
• Resets on each generation run (unless using same seed)

Next Steps

• UUID Generator - Alternative for unique IDs
• Number Generator - For random integers
• References - Use sequence IDs in relationships