Archivists manually identify and establish the relationships that provide the rich and engaging experience for people who explore the Digital Archive. These explicit relationships are stored in database tables. In contrast, the Digital Archive software automatically recognizes and displays certain implicit relationships without requiring any input from archivists. This page explains how archivists work with relationships.
It’s easy to establish a relationship between two Omeka items in the Archive. You simply edit one of the two items, select a relationship type, and enter the Identifier number for the other item. The admin page where you add relationships looks like this:
Adding a New Relationship
Here are the steps for adding a new relationship between two items:
- Edit either of the two items.
- Click the Relationships tab which appears when the AvantRelationships plugin is installed.
- Choose a relationship type from the dropdown list in the bottom row of the Relationships table.
- Enter the Identifier number for the related Item.
- Click the Add button.
The relationship is added immediately provided that the relationship’s rules are satisfied.
If rule validation fails, an error message appears explaining why the relationship was not accepted. The error message, like the one shown below, tells you what is wrong based on the rules. Close the error, make a correction, and try again.
This error is telling us that item 5932, which has Type “Image, Photograph”, cannot be the first item in a married to relationship because the relationship must be between Reference items about people. In this case, the archivist attempted to relate a photograph of Mrs. Higgins to the Reference item for Mr. Higgins (item 13178). However, in the Archive Relational Model, a married to relationship can only be established between two items when both items are Reference items about people. The correct use of the married to relationship for Mr. and Mrs. Higgins appears in the next screenshot.
The software’s enforcement of the relational model, and its validation of relationship rules, help ensure relational data integrity and makes it very difficult for an archivist to inadvertently create an inappropriate relationship. If you do manage to make a mistake, you can fix it in a few seconds.
Working with Either Item in the Relationship
As stated in the steps above for adding a relationship between two items, you can work with either item. The screenshot near the top of this page shows the Relationships tab for item 5932 which has a depicts relationship to item 13179. The screenshot below shows what the relationships look like when you edit item 13179 instead of item 5932. Now you see that item 13179 is depicted by item 5932. That’s because you are viewing the relationship from the opposite direction and the software has automatically inverted the relationship (depicted by is the inverse of depicts). The ability to view, set, and edit relationships while editing either item makes relationship management easy and intuitive.
Removing or Editing an Existing Relationship
To remove a relationship, click its Remove button and then click OK on the confirmation dialog. To edit an existing relationship, click its Edit button, select a different relationship type and/or type a different item number, and click the Update button as shown below.
Note that the Add, Edit, and Remove actions occur immediately without the need to click the Omeka Save Changes button (but be sure to click it if you made changes on any other tab). It works this way to keep you from adding or editing multiple relationships only to learn about errors after attempting to save the item. Instead, each change is either applied immediately or an error message is displayed for the current edit.