The Excel User's Guide to Databases: Migrations

SQL is great. In fact, it's probably the language I'm best at (although this may not mean much). The issue is that when you're building an application, you're primarily writing in an object oriented programming language like JavaScript or Python. These things work differently than SQL.

If you want to issue SQL statements against your database from your web app, you'd need to create these large, unwieldy strings:

    var database = database.connect()
    var sql_statement = """
      SELECT 
      …
      …
    """
    database.execute(sql_statement)

When statements get sufficiently complex – especially when you need to interpolate custom data into them before you send them to the database – this makes for a frustrating developer experience.

What an ORM does is bridge the gap between these two things – SQL and object oriented programming – by wrapping around your database with nice, ergonomic functions that more closely map to how developers build apps. In short, using an ORM is the difference between this:

    SELECT 
      username, 
      email 
    FROM users 
    WHERE user_created_at = '01-01-2022'

And this:

var user  = users.where({ user_created_at: '01-01-2021' })