Understanding Cardinality Types
Cardinality types are an important concept in building software applications. They help define how different objects interact with each other, which is essential to building complex and efficient applications.
Let’s use an example to help you understand how cardinality types of work. Imagine you are building an application for a small retail store that sells products to customers. You will need to keep track of your inventory and your customers.
One-to-One: One-to-One Cardinality is a relationship where one Object is associated with only one instance of another object and vice versa.
In our example, a customer can have only one membership account, and each membership account is associated with only one customer. This is an example of a One-to-One Cardinality relationship.
One-to-Many: One-to-Many Cardinality is a relationship where one Object is associated with many instances of another object, but the reverse is untrue.
In our example, each customer can have multiple orders, but each order can be associated with only one customer. This is an example of a One-to-Many Cardinality relationship.
Many-to-Many: Many-to-Many Cardinality is a relationship where one Object is associated with many instances of another object and vice versa.
In our example, each product can be included in many orders, and each order can include many products. This is an example of a Many-to-Many Cardinality relationship.
When to Use Cardinality Types
Cardinality types are used to define relationships between objects. By doing so, they can help you:
• Establish a relationship between two objects.
• Specify how objects interact with each other.
• Simplify the process of linking multiple objects.
In our retail store example, cardinality types can help you keep track of your inventory and customers. By defining the relationships between objects such as orders, products, and customers, you can build a complex and efficient application that simplifies managing your business.