Kysely: Type-Safe SQL Query Builder for Node.js (2026)

Short summary

A comprehensive guide to Kysely, a type-safe SQL query builder for Node.js that models SQL directly in TypeScript without ORM abstractions. Covers setup with PostgreSQL, database type definitions using Generated and ColumnType helpers, the singleton pattern for Next.js to prevent connection pool exhaustion, and basic select queries with full type inference. Compares Kysely against ORMs like Prisma and Drizzle, emphasizing exact query control and no N+1 surprises.

• •Kysely provides type-safe SQL query building with compile-time column and table validation
• •Covers setup, typed database interfaces, Next.js singleton pattern, and production query patterns
• •Contrasted with ORMs (Prisma, Drizzle) — no relation magic, explicit JOINs, exact result types

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