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How is a many to many relationship class created?
For many-to-many relationship classes, a new table is created in the database to store the foreign keys used to link the origin and destination classes. This table can also have other fields to store attributes of the relationship itself that are not attributed to either the origin or destination class.
What are the properties of a relationship class?
The feature classes participating in a relationship class will also be read-only in ArcGIS for Desktop Basic. A relationship class contains several properties that define how objects in the origin relate to objects in the destination.
When to use an association class vs attribute?
An association class allows you to record additional facts about a link between instances of the other two classes, such as the point in time the link came into existence. Association classes are like associative entities in a database. I think part of your question is also about when to use an association vs when to use attributes.
What are the properties of a relationship class in ArcGIS?
The feature classes participating in a relationship class will also be read-only in ArcGIS for Desktop Basic. A relationship class contains several properties that define how objects in the origin relate to objects in the destination. You specify these properties when you create the relationship class.
How to handle a many to many relationship in database?
Many-to-many: Multiple records in one table are related to multiple records in another table. Handling a one-to-one relationship or a one-or-many relationship can be done by adding the primary key of one table into the other table as a foreign key. However, for many-to-many relationships, it’s a bit different. Let’s have a look at an example.
What does a joining table do in a many to many relationship?
A joining table is a table that sits between the two other tables of a many-to-many relationship. Its purpose is to store a record for each of the combinations of these other two tables. It might seem like a bit of work to create, but it’s simple to do and provides a much better data structure.
What does many to many mean in relational model?
In the relational model, the many-to-many association between Orders and Products has turned into a one-to-many relationship between Orders and Order Lines, plus a many-to-one relationship between Order Lines and Products.