Relationships Between Items

This topic describes terms and concepts that help you understand the relationships between items in an application.

Primary Items

An application uses its primary table to define a single type of primary item. The primary table determines the set of data fields the primary item contains. At runtime, when a primary item is created, it occupies a row in the primary table. This means that all items created in an application have the same set of data fields, but the value of any particular field will be specific to the particular item or row in the primary table.

All of the workflows in an application create and process the same type of items. However, each workflow can be designed to process the various data fields in the item in a different way.

Primary items are created by Submit transitions. These transitions can be initiated directly by a user, or indirectly from an existing item through a Post, Subtask, Copy, or Publish transition. After items are created, they can be connected through a link or a relational field reference.


Links use a built-in attachment mechanism that is available in all workflows. Users can explicitly create links between existing items. Links can be created implicitly through Post, Subtask, Copy, or Publish transitions. With implicit link creation, a link can be created between the existing (original) item that is being transitioned and the new item.

Links can connect items in the following ways:
  • The original item connects to the new item (one-way link).
  • The new item connects to the original item (one-way link).
  • The original item and the new item connect to each other (two-way link).
Note: The Subtask transition implicitly creates a two-way link that appears in the Subtasks section of the item. You can optionally configure the Subtask transition to create item links in addition to the Subtask section links. These links appear in the Attachments section of the item.

Relational Field References

Note: In this section, "relational field references" means relationships between items established through Single Relational and Multi-Relational fields. These fields can be in applications in the same process app or in applications in other process apps. (In the latter case, you must first create a reference to the application in the other process app. This is a different type of reference. For more information, see About References.)

Relational field references are often used to model parent-child relationships between items where the parent item stores a reference to one or more child items in a Relational field. This creates a one-way, one-to-one or one-to-many relationship.

You can also use relational field references to create multiple relationships, two-way relationships, and chains of relationships between items. An additional Relational field must be added to the primary table of the referencing item for each additional relational field reference. For example, to create a two-way relationship between items from two different applications, each primary table must define a Relational field that points to the primary table of the other application.


Links, subtasks, and references allow items that have a relationship to be transitioned automatically when one of the related items is transitioned. There are three mechanisms for this:
  • Subtask transitions work with Subtask attachment links.
  • Transition actions allow an item to automatically transition another item that it references or that references it. Transition actions work with references.
  • Trigger actions work across applications that may be aware of each other, but do not have to be. Trigger actions can be configured to work with subtasks, references, and links.

Related Topics

Application Workflow Overview

Using Actions