ORMs solve one problem and create three others: magic behavior you didn't ask for, performance you can't tune without fighting the abstraction, and SQL you can't read when something goes wrong. Kysely takes a different position — it models SQL directly in TypeScript. You write what looks like SQL, TypeScript checks every table name, column reference, and result type at compile time, and you're never surprised by what query gets generated because you wrote it yourself.
This guide covers Kysely from initial setup through real production patterns: typed queries, joins with inferred result types, transactions, migration management, and the singleton pattern for Next.js.
What Kysely Is (and Isn't)
Kysely is a query builder, not an ORM. The distinction matters:
ORM (Prisma, Drizzle with relations): defines your schema once, generates queries, manages relations, abstracts SQL
