What is Object Relational Mapping?


With the use of object-relational mapping (ORM) technology, programmers can deal with data without having to adhere to the OOP paradigm.

In a structure that is difficult to comprehend and grasp, object-oriented programming uses several states and codes. To make it easier for developers to comprehend the underlying database structure, ORMs convert the data and produce a structured map.

Mapping clarifies how objects link to various tables. These details are used by ORMs to translate data between tables and provide the SQL code needed by a relational database to insert, update, create, and remove data in response to changes made to the data object by the application.

You won’t need to write any additional low-level code after writing the ORM mapping, which will take care of the application’s data requirements.

In layman’s language, ORM relational databases and OOP languages can’t coexist with other types of systems, hence ORM transforms data between them.

How Does ORM Work?

Object-oriented runtime environments (ORMs) create abstract models of object-oriented programs. In other words, it generates logic on a good level even though the inner workings of the code are hidden.

Without knowing the exact structure of the data, mapping explains the connection between an item and the data. In order to handle data operations, SQL code must be connected to the application via the model.

The developer will save a ton of time because this type of “plumbing” code does not need to be rebuilt. Some OOPs languages and ORMs that are interrelated are mentioned below:

  • .NET Framework and Microsoft Entity Framework
  • PHP and Doctrine
  • JAVA and Hibernate
  • C# and Dapper ORM

Advantages of ORM

As object relational mapping reduces the amount of SQL expertise needed to connect a database to an application, ORM technologies are well-liked among OOP developers.

You can concentrate on creating business logic by using ORMs to automatically construct the SQL code. Here are some of the key advantages associated with ORM.

  • By utilizing the concept of data abstraction, ORM enhances data security.
  • You do not need to invest as much time in testing the data-access code because the code created by the ORM has been well tested.
  • It eases the burden on coders by decreasing database query handling.
  • Large-scale procedures can be saved in the front end rather than being stored in the back end of the applications. This enhances adaptability to changes.
  • Making a class library to produce a different dynamic-link library is one technique to reuse data. The data-access code does not have to be repeated when creating a new application.
  • You will utilize best practices for application design by a well-written ORM’s implementation of design patterns. The ideal database schema need not be created in advance if an ORM is used to handle the data interface. It becomes possible to change the current interface without much difficulty.

Disadvantages of ORM

While many applications find ORMs to be a great tool, some developers have found that utilizing ORMs for data-access apps has a number of disadvantages. The difficulties appear to be related to the application’s complexity. Some disadvantages of ORM are as follows:

  • The extra code that the ORM generates is a typical gripe among OOP developers. The performance of the application gets slow due to the extra code, and maintenance becomes more difficult.
  • An ORM’s initial configuration can be difficult.
  • An improper mapping between data tables and objects can occasionally be produced by ORMs. These issues can hinder applications and are difficult to identify.
  • It takes time to learn ORM from scratch.
  • It can be hard to improve data structures when the ORM layer is poorly developed. Your alternatives may become limited by it depending on the ORM. It’s more difficult to write migrations in OOP than it is to write them in SQL if your ORM doesn’t support them.

Key Features of ORM

Following are the key features of ORM:

  • With ORM, you can create a general query because the application is no longer dependent on the backend database management system.
  • SQL syntaxes for each database that is being used to provide application support don’t need to be learned separately, which saves coders time.
  • As there is a minimal requirement for coding, the link becomes strong and secure.
  • There are no limitations while dealing with data because ORM can handle all changes, no matter how big or tiny.


In this blog, you have learned what object-relational mapping (ORM) is all about, along with its advantages and disadvantages. In small to medium-sized projects, it is good to utilize ORM to lessen impedance mismatch. Depending on the needs of the business, this may be incorporated wherever necessary.

Some front-end technologies are only appropriate for use with certain front-end languages, such as when Java and Hibernate are combined. Hence, the choice is made depending on the application programming technique used for mapping with a database.

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