Using MySQL with ORMs: Django, Rails, and Prisma

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The Settings That Matter Everywhere

• The connection uses utf8mb4, or emoji break in transit. See utf8mb4 and emoji.
• Strict SQL mode is on (it is the MySQL 8.x default), so bad data errors instead of silently truncating.
• The pool size is deliberate. Every framework opens a pool per process; multiply by your process count before picking a number. See Connection pooling.

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Django

DATABASES = {
    "default": {
        "ENGINE": "django.db.backends.mysql",
        "NAME": "myapp",
        "USER": "app",
        "PASSWORD": environ["DB_PASSWORD"],
        "HOST": "127.0.0.1",
        "PORT": "3306",
        "OPTIONS": {
            "charset": "utf8mb4",
            "init_command": "SET sql_mode='STRICT_TRANS_TABLES'",
        },
    }
}

• Use mysqlclient, the maintained C driver Django’s docs recommend.
• Django emulates some constraints in Python; add real database constraints too (unique=True becomes a real unique index, but check constraints need CheckConstraint in Meta).
• select_related() (JOIN) and prefetch_related() (second query) are the N+1 tools; see below for when.

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Rails

# config/database.yml
production:
  adapter: mysql2
  database: myapp
  username: app
  password: <%= ENV["DB_PASSWORD"] %>
  host: 127.0.0.1
  encoding: utf8mb4
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>

• encoding: utf8mb4 in database.yml sets both the connection charset and the default for rails db:create.
• ActiveRecord validations (validates_uniqueness_of) race under concurrency; back every uniqueness validation with a real unique index, and let the 1062 duplicate-key error be the last line of defense.
• includes is the N+1 tool; strict_loading mode turns lazy loading into an error so N+1s fail in development instead of shipping.
• Rails 8.1 generates max_connections in database.yml where older versions generated pool. A pool: key still works, silently, as the fallback max_connections reads; setting both to different values raises at boot. See Rails 8 with MySQL for a full app, including the --database=mysql flag Rails 8 needs since it no longer defaults there.

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Prisma

datasource db {
  provider = "mysql"
  url      = env("DATABASE_URL")
}

DATABASE_URL="mysql://app:password@127.0.0.1:3306/myapp?connection_limit=10"

• Prisma speaks utf8mb4 by default; the setting to watch is connection_limit in the URL, which defaults low.
• prisma migrate generates DDL from schema drift. Read the generated SQL before applying to production, exactly as you would a hand-written migration. See Schema migrations.
• Relation queries use include; the N+1 shape appears when you loop over results and access relations one by one.
• Prisma 7 moves the connection URL above out of schema.prisma and into a separate config file, and requires a driver adapter to connect. See Next.js and Prisma with MySQL for a full Prisma 7 app.

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The N+1 Problem, Once

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When to Drop to SQL

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See also

• Next.js and Prisma with MySQL — a full app on Prisma 7, not just the config
• Next.js and Drizzle with MySQL — a full app on Drizzle, a lighter, SQL-first alternative not covered above
• Next.js with MySQL — connection setup and query patterns with no ORM at all
• Rails 8 with MySQL — a full app, including the scaffold flag Rails 8 needs to pick MySQL at all
• Laravel 12 with MySQL — a full app on Laravel’s Eloquent ORM, not covered above
• Go and sqlc with MySQL — generated, type-safe queries instead of a runtime ORM
• Connection pooling — sizing pools across processes
• utf8mb4 and emoji — the charset setting every config above sets
• Slow query log — catching what the ORM generates
• Schema migrations — applying ORM-generated DDL safely