What are the differences between using ORM and direct SQL queries when working with a database?

Main differences between using ORM and direct SQL queries:

• Level of abstraction: ORM (Object-Relational Mapping) allows working with the database through objects and classes, hiding SQL details. Direct SQL queries require writing and maintaining SQL code.

• Productivity: ORM speeds up development as it reduces the need to write a lot of SQL. Direct queries offer more control but take more time.

• Performance: Direct SQL queries can be manually optimized and work faster in complex cases. ORM sometimes generates less efficient queries.

• Security: ORM generally protects against SQL injection through query parameterization. With direct SQL, you need to ensure security yourself.

• Flexibility: Direct SQL queries give full control over the queries, which is important for complex operations. ORM is limited by the mapping capabilities.

Example of using ORM (Entity Framework in C#):

using(var context = new AppDbContext())
{
    var users = context.Users.Where(u => u.IsActive).ToList();
}

Direct SQL query:

using(var context = new AppDbContext())
{
    var users = context.Users
        .FromSqlRaw("SELECT * FROM Users WHERE IsActive = 1")
        .ToList();
}

The choice depends on the project requirements and tasks.