Entity types, link types, and property types

Entity types and link types

In an i2 Analyze schema, entity types and link types have similar definitions. Among several common features, entity types and link types both have:

• Identifiers, so that types can refer to each other in rules about their relationships

• Names that users see when they interact with entities and links of particular types

• Definitions of the properties that entities and links of particular types can contain

As well as the common features, each entity type contains the icon that represents entities with that type in visualizations. Link types do not contain icons, but they do contain lists of 'from' and 'to' entity type identifiers. For a link that has a particular link type, these lists determine what entity types the entities at each of the link can have. For example, a link of type Calls might be valid in both directions between two entities of type Person. An Owns link might be valid between a Person and a Car, but would not be allowed in the opposite direction.

For an i2 Analyze schema to be valid, any identifiers that appear in the 'from' and 'to' lists of link types must also appear as the identifiers of entity types.

Property types

In an i2 Analyze schema, entity types and link types both contain property types. For an entity or link record that has a particular type, the property types specify the names and the logical types of the properties that the entity or link can have.

Note: This representation is simplified. A property type can also specify a list of possible values for properties of that type. Furthermore, it can declare whether a property of that type is mandatory for an entity or a link that has the containing type.