ORM - advantages and disadvantages



14 Nov 2023




ORM - advantages and disadvantages

Object-Relational Mapping (ORM)

Object-Relational Mapping (ORM) is one of the key technologies in today's programming world, offering developers a convenient tool for manipulating database data. In this article, we will closely examine both the benefits and challenges associated with using ORM, highlighting their impact on code efficiency, readability, and application performance. Our goal is to see the advantages advanced ORM mechanisms bring, as well as the potential difficulties that may arise in their application.

Advantages of ORM:

  • Speed and Efficiency: Undoubtedly, one of the advantages is the speed and efficiency of database operations. Developers using ORM can manipulate data using objects instead of complex SQL queries. This significantly speeds up the programming processes, especially in projects where much attention is given to business logic rather than complex database operations.
  • Code Conciseness: Using ORM makes the code concise and readable. Database operations are expressed in an object-oriented language, making it easier to understand and maintain the code. In large projects where tens or even hundreds of thousands of lines of code can complicate team collaboration, conciseness is a key element.
  • Easy Object-Relational Mapping: Automatic object-relational mapping is a milestone in simplifying programming life. What once required complex manual operations is now handled automatically. Developers can design a system based on objects, and ORM takes care of properly mapping them to database structures.
  • Independence from a Specific Database: Migration between different databases becomes easier. With ORM, the code is not tightly bound to a specific database platform. This means that a project can be easily moved to a new database without the need to rebuild a significant portion of the code.
  • Testing Ease: ORM can facilitate testing since database operations can be replaced with operations on in-memory objects. This allows for easier writing of unit tests, which is crucial for maintaining high software quality.
  • Maintenance of Data Consistency: ORM mechanisms ensure data consistency by controlling relationships between objects. In traditional databases, this task often falls on the programmer, leading to errors and difficulties in maintaining data consistency.

Disadvantages of ORM:

  • Excessive Abstraction: The first disadvantage that arises is excessive abstraction. ORM mechanisms try to hide implementation details, which can lead to a loss of control over what exactly happens in the database. For advanced scenarios where precise control over SQL queries is essential, this can be a problem.
  • Lack of Control over SQL Queries: In the case of more complex queries, programmers may lose control over the SQL generated by ORM. Query optimization becomes more challenging, and the efficiency of database operations may be lower than with manually written SQL.
  • Unnecessary Complexity for Simple Projects: For smaller, simpler projects, using ORM may introduce unnecessary complexity. An additional layer of abstraction can make the code harder to understand, especially for less experienced programmers.
  • Performance: Despite the convenience ORM brings, it may impact application performance. Automatically generated SQL queries may be less optimal than those written manually by an experienced programmer. In situations where every millisecond matters, manually writing SQL queries may be necessary.
  • Learning and Implementation Cost: For new programmers, learning to use ORM can be time-consuming. Complex mechanisms, configurations, and differences between various ORM frameworks can be challenging, especially for those who are just starting their programming journey.


In the context of ORM's pros and cons, understanding the project's context is crucial. Large, complex systems can benefit from the code conciseness and easy object-relational mapping that ORM offers. On the other hand, in smaller projects where simplicity is a priority, an additional layer of abstraction may be unnecessary. Understanding the project's specifics and the programming team's experience is essential to make an informed decision regarding the use of ORM.

Emphasizing the role of performance and control over SQL queries is crucial in the context of large projects where the efficiency of database operations is critical. On the other hand, the flexibility and ease of maintaining data offered by ORM are invaluable in projects where dynamism and changes in data structure are frequent.

It's worth noting that the choice between using ORM and raw SQL is an individual decision, and understanding the project's context is key to achieving an optimal solution. Each tool has its place in the right context, and the choice between them should be conscious and tailored to the specific requirements of the project.