In this article, we are going to learn about the Business Logic Layer in Database Management systems. The Business Logic Layer also known as BLL act as an intermediate between the Presentation Layer and the Data Access Layer (DAL). This layer handles the business logic, business rules as well as calculations. It tells how the data from the database can be used, what it can perform, and what can not within its application.
The Business-Logic Layer (BLL) is a component of a software architecture that is responsible for implementing the business logic of an application. It sits between the presentation layer (e.g., the user interface) and the data access layer (e.g., the database), and is responsible for processing and manipulating data before it is presented to the user or stored in the database.
The BLL is responsible for performing tasks such as:
-Validating input data to ensure that it meets the necessary business rules and constraints.
-Performing calculations and transformations on data, as required by the business logic.
-Enforcing business rules and policies, such as access control and security.
-Communicating with the data access layer to retrieve and store data.
-Handling errors and exceptions.
The BLL is designed to be reusable and independent of the user interface and data storage implementation. This allows the application to be easily modified or extended without affecting the underlying business logic.
The BLL is also responsible for managing the workflows and the use cases of the application, by handling the communication between the different layers, and by implementing the rules and constraints of the business.
In summary, The Business-Logic Layer (BLL) is a component of a software architecture that is responsible for implementing the business logic of an application. It sits between the presentation layer and the data access layer, and is responsible for processing and manipulating data before it is presented to the user or stored in the database. It also manages the workflows and the use cases of the application, and it is designed to be reusable and independent of the user interface and data storage implementation.
- Presentation Layer: The layer at which users interact with the application and the final data will be visible to the users at this interface. It acts as an interface between the user and the application.
- Business Logic Layer: It acts as an intermediate between the Presentation and the Data Access Layer.
- Data Access Layer: The layer at which the data is managed.
Business Logic Layer
- All the three layers above play an important role in building an application
- The business logic layer manages the communication between the database and the presentation layer.
Example: In an application, when the user access it or write queries in it with the help of a presentation or user interface layer the business logic layer helps the user to get a response to the asked queries by transferring it to the Data Access layer which further processes the query and give the suitable result to a business logic layer which is further transferred to the presentation layer which makes it visible to the user.
Due to the less clarity in defining the Business logic layer, some business domains like Microsoft and Apple excluded the BLL from their applications which leads to difficulty in code maintenance. A better approach is to build an application that supports multiple different user Interfaces.
Advantages of Business Logic Layer:
- Code Maintenance is easy: Maintaining the code will be easy when we are using the Business Logical Layer as it supports multitier architecture. By using this we can easily determine any kind of change in the code.
- Security: This architecture provides us the security as we can see that the Presentation layer doesn’t directly interact with the Data Access Layer which prevents it from any kind of data loss and ensures that the data is secure at the Data layer.
- Application releases: It makes application release rollout easy. Because the Business Logic Layer is the only one to be updated every time then we do not need other layers of architecture i.e. the Presentation layer and the Data Access Layer.
- Ease of learning: It is easy to learn because the learner has to specialize only in the presentation, data, and business layer to more quickly learn the specific parts of the application. The development time taken by the application will be small as all the layers can work together at the same time.
Disadvantages of Business Logic Layer:
- Expensive: It will be very difficult and expensive to install and maintain this layer in databases.
- Source control is very difficult to perform properly with existing procedures.
- It makes it difficult to use the code, again and again, such that it decreases code reusability.
Applications of Business Logic Layer:
- BLL has a major application in building multi-tier applications.
- It is most commonly used in creating component-based applications.