Key Roles and Property Types

Define node properties with 12 abstract types and 6 key roles. Configure constraints including required, nullable, unique, and indexed. Add per-property projections (search, API, persistence), governance metadata (description, example, tags), and validation rules with min/max values, patterns, and enums.

February 5, 2026

Graph diagram nodes support typed properties similar to database columns. Each property has a data type, optional key role, and constraints. In Graph DB mode, these properties are used for Cypher export and schema validation.

Property Types

NeoArc supports 12 abstract property types. These map to platform-specific types during export (e.g. Neo4j, SQL, search indices).

Type	Description	Example Values
string	Text values	"John Doe", "SKU-12345"
int	Whole numbers	42, -17, 0
float	Decimal numbers	3.14, -0.5, 99.99
boolean	True/false values	true, false
date	Date without time	2026-02-05
datetime	Date with time	2026-02-05T14:30:00Z
uuid	Universally unique identifier	550e8400-e29b-41d4-a716-446655440000
json	Structured JSON data	{"tags": ["vip", "active"]}
enum	Enumerated value from a fixed set	"active", "inactive", "pending"
array	Ordered list of values	["tag1", "tag2", "tag3"]
object	Nested key-value structure	{"address": {"city": "London"}}
number	Generic numeric value (int or float)	42, 3.14

Key Roles

Key roles indicate how a property functions in the data model. These appear as badges (PK, FK, NK, etc.) next to property names.

Role	Badge	Purpose	Validation
Primary	PK	Single-column primary identifier	Must be unique, typically uuid
Natural	NK	Business-meaningful unique identifier	Must be unique, often string
Surrogate	SK	System-generated identifier	Auto-generated, typically uuid or int
Composite Part	CP	Part of a composite key	Combined with other CP properties for uniqueness
Foreign	FK	Reference to another node	Must reference valid target node/property
None	(none)	Regular property	No special key constraints

Key Role Examples

Constraints

Properties support four constraint flags that control data integrity.

Required

Property must have a value. Displayed with red badge.

Nullable

Property can be null. Opposite of required.

Unique

Value must be unique across all nodes of this type. Green badge.

Indexed

Property is indexed for faster queries. Blue badge.

Validation Rules

Properties can have validation rules that constrain acceptable values. These are enforced during schema validation and exported to Cypher constraints.

Rule	Applies To	Description
minValue	int, float	Minimum numeric value (inclusive)
maxValue	int, float	Maximum numeric value (inclusive)
minLength	string	Minimum character length
maxLength	string	Maximum character length
pattern	string	Regular expression pattern
enumValues	string	List of allowed values

Validation Rule Examples

// Price must be positive
{
  "name": "price",
  "type": "float",
  "minValue": 0.01
}

// Status must be one of the allowed values
{
  "name": "status",
  "type": "string",
  "enumValues": ["pending", "active", "completed", "cancelled"]
}

// Email must match pattern
{
  "name": "email",
  "type": "string",
  "pattern": "^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z]{2,}$"
}

Foreign Key Resolution

Foreign key properties can reference specific properties on other nodes. This creates a navigable relationship in the schema.

Description Field

Every property supports a description field for documentation. Descriptions appear in tooltips and are included in Cypher export comments.

Default Values

Properties can specify default values that apply when no value is provided. Defaults are type-specific:

Type	Default Examples
string	"unknown", "N/A", ""
int	0, -1, 100
float	0.0, 1.0
boolean	true, false
date	Current date expression
datetime	Current timestamp expression
uuid	Generated UUID expression
json	{}, []

Per-Property Projections

Each property supports projection flags that control how it appears across derived artefacts. Projections are configured in the property details panel.

Search Projection

Include in search indices. Controls whether the field is searchable, filterable, sortable, or used as a facet.

API Projection

Include in API responses. Controls field visibility in generated REST or GraphQL schemas.

Persistence Projection

Include in the persistence layer. Controls whether the field is stored in the database.

Custom Projection

User-defined projection for project-specific concerns such as audit trails, reporting, or analytics.

Governance Metadata

Properties support governance metadata fields that improve documentation quality and support automated tooling.

Field	Purpose
Description	Documents the property's purpose, expected values, and usage context. Included in Cypher export comments and tooltips
Example	A representative example value. Helps consumers understand the expected format and content
Tags	Free-form tags for categorising properties (e.g. PII, financial, audit). Used for filtering and compliance reporting

Adding Properties

Mode Visibility

Property editing features vary by authoring mode:

Feature	Mind Map	Conceptual	Graph DB
Property panel	Hidden	Basic	Full
Key role selection	Hidden	Shown	Enforced
Type selection	Hidden	Hidden	Shown
Constraints	Hidden	Hidden	Shown
Validation rules	Hidden	Hidden	Shown
FK resolution	Hidden	Hidden	Shown