Resources must be loaded into an Ed-Fi ODS / API instance according to a set dependency order.

Dependency Order Overview

The dependency order is enforced through entity relationships in the ODS database or by authorization.

Dependency order enforced by the entity relationships. Like in any relationship-based database, many entities in the ODS have foreign key relationships with other entities. The ODS / API will return validation errors if constraints for these relationships are not met. While loading or updating data it is important to consider these dependencies to avoid validation errors from the database.
Dependency order enforced by authorization. Many resources in the ODS / API are authorized by their relationship to education organization and/or people. For example, access to Student and student-related data is restricted by the StudentSchoolAssociation. The same is true for staff members and their relationships provided by the StaffEducationOrganizationEmploymentAssociation and the StaffEducationOrganizationAssignmentAssociation. Access to Parent information is restricted by the accessible Students and their StudentParentAssociations. For example, if "Student A" is accessible, then any Parents to which Student A has a StudentParentAssociation will be accessible as well.

A high-level dependency graph is shown below:

Dependency Order Endpoint

As an API client developer, it is useful to know the dependency order of resources to load the data and minimize authorization and validation errors in API responses.

The ODS / API provides a dependency metadata endpoint at /metadata/data/v3/dependencies to show this dependency order based on each HTTP operation. The default GET generates a JSON response with an order group of resource endpoints that can be loaded at the same time. The response also includes the "Create" and "Update" operations that can be performed in that order group. "Delete" operations are to be performed at the reverse order of Create operations. API Client developers can use this as documentation or can use it programatically for orchestration of API calls.

The Postman screenshot below shows the GET call:

Adding a header Accept with a value of application/graphml can be passed to obtain dependency output in the graphml XML format. The Postman screen shot below shows the GET call with the added header:

The screenshots bellow show the dependency order enforced by authorization on the Students resource. You can see that Student creation is at order 3, StudentSchoolAssociation creation is at order 18 the Student update is at order 19. This shows that a client cannot edit a student record it has created until an enrollment record has been established.

A Postman screen shot showing the Student creation at order 3:

A screenshot showing the StudentSchoolAssociation creation at order 18:

A final screenshot showing the Student update at order 19, after the StudentSchoolAssociation creation:

Links

You can explore the dependency endpoint at the Ed-Fi Alliance-hosted sandbox:

Dependency Endpoint in Ed-Fi ODS / API Sandbox

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