Entity

An entity generally refers to a unique, identifiable, and separate item within a system. They are often used to model real-world objects or concepts within the system, acting as a blueprint for creating instances or objects.

Entities are initially created by AI and initially it really depends on the Prompt we gave in the ROQ's AI generator. If we want to change the generated application entities then we should change the Prisma schema.

Entity could be named anything, for example if you gave ROQ's AI generator with the this Prompt:

Boat Rental Platform is a comprehensive digital marketplace connecting boat owners and businesses for efficient, secure boat rental transactions. It provides real-time booking, customizable agreements, secure payment processing, and data-driven insights for better decision-making. With a scalable design, 24/7 customer support, and ability to cater to both short and long-term rentals, it's a robust solution for streamlining maritime rental processes.

ROQ's AI generator will create these entities:

• rental: This could represent an instance of a boat being rented, including the boat involved, the user who's renting it, the duration of the rental, the cost, and so on.

• user: This could represent an individual or business using the platform, with attributes such as name, contact information, payment information, rental history, and so on.

• platform: This could represent the rental platform itself, encompassing details such as its operating hours, the boats available, the users registered, and more.

• boat: This would represent a specific boat that can be rented, with attributes such as its size, type, availability, rental price, and so on.

Each instance of an entity would be a specific example, such as a particular rental transaction, a specific user, the platform at a specific moment in time, or a specific boat.

Project Entities

Project entities can be accessed in ROQ application console. Go to Users & Access → Project Entities. You can edit the existing entity, create a new entity, and add, edit, or delete the entity relationship.

Create An Entity

To create a new entity click + Create Entity button. For example, create a review entity, that could represent a review left by a user after a rental transaction.

Entity Relation

Relationships are established between different entities. The main types of relationships ROQ provides are: one-to-one, one-to-many, many-to-one and many-to-many.

For the example above, the review entity would relate to the user entity who left the review and the boat entity, which boat was reviewed.

There are another possibilies review entity relation. Here's how each Relation Type might relate to the review entity in your Boat Rental application:

1. One-to-One (1:1): This type of relationship means one entity is associated with one and only one entity. For example, if each review had a unique attachment (say, a photo or a document related to the review), this could be modeled as a one-to-one relationship between the review entity and an attachment entity.

2. One-to-Many (1:M): In this type of relationship, an entity can have multiple corresponding entities. For instance, a user can leave many reviews, but each review is left by one and only one user. So, the relationship between user and review is a one-to-many relationship from the user perspective.

3. Many-to-One (M:1): This is the reverse of a one-to-many relationship. Using the same example as above, each review is associated with one user, but a user can have many reviews. From the review perspective, the relationship with user is a many-to-one relationship.

4. Many-to-Many (M:N): In this type of relationship, multiple entities can be associated with multiple entities. For example, if users could tag their reviews with multiple tags (another potential entity), and each tag could be associated with multiple reviews, this would represent a many-to-many relationship. This type of relationship is usually resolved by creating a third, entity, which holds the relationship data, usually just IDs from the two related entity (e.g., review_tags).

Relation between review and user entity is Many-to-One relationship. A user can have many reviews but from reviews perspective, the relation is many to one user.

Let's take look about review entity and boat entity. A boat can have many reviews, but each review is associated with one and only one boat. This means that a single boat can accumulate multiple reviews over time, each left by a different user, or even the same user if they rent the boat more than once. However, a review can't be for multiple boats; it's associated specifically with the boat that was rented when the user left the review.

So from the review entity perspective, the relationship to boat entity is Many-to-One: many reviews can be related to one boat.

On the other hand, from the boat entity perspective, the relationship to review entity is One-to-Many: one boat can have many reviews.

Entity Foreign Key

It's always crucial to view the relationships from both perspectives to understand the nature of the relationship and to correctly model your data. Another important concept in the relatioship between entities Foreign Key Field. For instance:

• The user entity might have an attribute called userId, which is a unique identifier for each user.

• The boat entity might have an attribute called boatId, which is a unique identifier for each boat.

• The review entity would also have its own unique identifier, reviewId. However, it would also have userId and boatId as foreign keys, linking each review to a specific user and boat.

When a user creates a review for a boat, the system would record the userId and boatId along with the review. This way, the system can track which user left the review and which boat the review pertains to.

Using these foreign keys, it's possible to retrieve related data across different entities. For example, given a boatId, you could retrieve all reviews for that boat. Or given a userId, you could find all reviews left by that user.