Exercise 4: Creating relationships between objects
In Exercise 2: Importing data into your geodatabase, you imported an INFO table containing owner objects into the Montgomery geodatabase. The geodatabase already has a feature class, Parcels, that contains parcel objects. You will now create a relationship class between the parcels and the owners so that when you use the data in ArcMap, you can easily find out which owners own which parcels.
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Right-click the Landbase feature dataset in the Montgomery geodatabase, point to New, then click Relationship Class.
The New Relationship Class wizard opens.
- Type ParcelOwners in the Name of the relationship class text box.
- Click Owners in the Origin table/feature class list.
- Double-click the Landbase feature dataset in the Destination table/feature class list.
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Click Parcels.
This designates the Parcels feature class as the destination feature class.
- Click Next.
- Click Next.
- Type owns for the forward path label.
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Type is owned by for the backward path label.
- Click Next.
- Click 1-M (one-to-many) to specify that one owner can own many parcels.
- Click Next.
- Click Next.
- Click the first drop-down arrow under Select the primary key field in the origin table/feature class and click PROPERTY_ID.
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Click the second drop-down arrow on the dialog box and click PROPERTY_I for the embedded foreign key in the destination feature class.
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Click Next.
A summary page appears.
- Review the summary page to make sure the information is correct.
- Click Finish.
The first panel of the wizard is used to specify the name, origin, and destination feature class or table for the new relationship class.
The next panel is used to specify the type of relationship class you are creating. You are creating a simple relationship class, since owners and parcels can exist in the database independently of each other. You can, therefore, accept the default type—Simple (peer to peer) relationship.
You must now specify the path labels and the message notification direction. The forward path label describes the relationship as it is navigated from the origin class to the destination class—in this case, from Owners to Parcels. The backward path label describes the relationship when navigated in the other direction—from Parcels to Owners.
The message notification direction describes how messages are passed between related objects. Message notification is not required for this relationship class; therefore, you can accept the default of None.
You will now specify the cardinality of the relationship. The cardinality describes the possible number of objects in the destination feature class or table that can be related to an object in the origin feature class or table.
You must now specify whether your new relationship class will have attributes. In this example, the ParcelOwners relationship class does not require attributes, which is the default.
The next step is to specify the primary key in the origin table (Owners) and the embedded foreign key field in the destination feature class (Parcels). Owners and Parcels that have the same value in these fields will be related to each other.
You have now added a second kind of behavior to the geodatabase—relationships.
Next, you will continue to add behavior to the geodatabase by creating a geometric network and defining connectivity rules. See Exercise 5: Building a geometric network.