Associations model relationships between features that are not geometrically coincident. This allows modeling connectivity between features that are not coincident, the structural support of assets, and features contained within other features.
The utility network has the following types of associations:
Each type of association has its own type of network rule that can be created to ensure data quality by restricting the types of features that can be associated. These rules are enforced when creating associations using the Modify Associations pane and also when importing. If a rule does not exist to support an association, the Import Associations tool will fail.
Work with associations
Associations are created, modified, and deleted using the Modify Associations pane. This is where association rules are checked to ensure the selected features can connect, attach, or be contained. You can create network rules to allow associations to be established between features as long as utility network feature restrictions are honored.
All features in a utility network have an attribute called Association status. It indicates the type of association a feature participates in, the role the feature plays in the association relationship, and any properties that are set, for example, visible content. This attribute is used to control the visibility of associations in the map.
See Association status attribute for more details.
Associations do not have attributes or a Shape field, and they do not support relationship classes or join tables. Associations are internally managed in a system table. Although associations do not have a Shape field, you can view them using the following workflows:
- Click the Modify Associations pane to interactively view associated features. For example, by clicking the Containment tab and selecting a container feature on a map, you can see features that are content. Connectivity associations will also show terminals for associated features if they exist.
- Create a network diagram to visualize the associations in a diagram view.
- Click the View Associations button to view connectivity or structural attachment associations.
- Click the View Content drop-down menu to show or hide containment association content. This enables or disables display filters configured using the association status attribute to turn content feature display on and off based on their visibility property.
See Control association visibility for more information about viewing associations.
Structural attachment and containment associations require that an appropriate association role be assigned to the datasets representing the structure or container features. Use the Set Association Role tool to designate the specific association role type along with additional properties. The Role Type of Structure or Container is assigned to feature classes using specific asset groups and asset types. An association role must be set before creating structural attachment and containment rules. Association roles are assigned to datasets that can be a structure in a structural attachment association and a container in a containment association. Once an association role is assigned, features from these datasets can be included in an association as long as they have supporting network rules.
- Container—Features can be a container in a containment association. All structure and domain network datasets can serve as a container.
- Structure—Features can be a structure in a structural attachment association. The structure junction and structure junction object datasets can serve as a structure.
To review valid structural attachment and containment relationships, see Feature restrictions.
To determine if a dataset has an association role set, review the Network Properties tab for the utility network. From here, expand the appropriate domain or structure network and inspect the Association Role column for specific asset groups and asset types.
Review the section below for additional properties that are set for association roles.
Deletion Semantics, View Scale, and Container Split Policy
Additional properties can be defined with the Set Association Role tool. The properties are applicable to specific association roles and will vary depending on the specified Role Type. See the list of association properties and if they apply to a container or structure.
- View Scale—Container only
- Deletion Semantics—Container and structure
- Container Split Policy—Container only (structure line feature class)
The View Scale property is specific to the container role. It determines what map scale to set when you enter containment mode, for example, 1:100. This property does not apply to junction and edge objects.
The Deletion Semantics properties apply to both the container and structure association roles. They determine how child features are handled when the parent feature is deleted. For example, if a pole structure is deleted, the deletion semantics control how the items that are attached are impacted. For containment, when the container is deleted, the deletion semantics control how content features are impacted.
There are three types of deletion semantics:
- Restricted—If content or attachment features exist, an error is returned when attempting to delete the container or structure. The content or attachment features must be removed before deleting the container or structure.
- Cascade—When a container or structure is deleted, its content or attachment features are also deleted.
- Set to none—When a container or structure is deleted, its content or attachment features are not deleted; instead, it is removed from the containment or structural attachment association.
The Container Split Policy property is specific to the container association role and only set for structure line feature classes. It is used to determine how content is treated when a container feature is split. The options for the container split policy are Do Not Split Content (default) or Split Content. If using a split policy of Do Not Split Content, a new container feature is created from the split operation and content is not split. The content feature is maintained as content to both parent containers. With the policy of Split Content, content features are also split and properly associated with the new container features created during the split operation.
To learn more, see Set or modify an association role assignment.