SvelteKit

SvelteKit connects to DB9 through any standard PostgreSQL driver over pgwire. DB9 is PostgreSQL-compatible, so no special adapter is needed.

This guide shows how to wire up a SvelteKit app with DB9 using Prisma for schema-first workflows and Drizzle for TypeScript-first query building.

Prerequisites

• A DB9 database (create one)
• Node.js 18+
• SvelteKit 2+

Create a DB9 Database

Terminal

db9 create --name sveltekit-app

Get the connection string:

Terminal

db9 db status sveltekit-app

Set the connection string as an environment variable:

.env

DATABASE_URL="postgresql://sveltekit-app.admin:YOUR_PASSWORD@pg.db9.io:5433/postgres?sslmode=require"

Setup

Prisma

Install

Terminal

npx sv create sveltekit-db9
cd sveltekit-db9
npm install prisma @prisma/client
npx prisma init

Schema

prisma/schema.prisma

generator client {
  provider = "prisma-client-js"
}

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

model Todo {
  id        Int      @id @default(autoincrement())
  title     String
  done      Boolean  @default(false)
  createdAt DateTime @default(now())
}

Push the schema to DB9:

Terminal

npx prisma db push

Generate the client:

Terminal

npx prisma generate

Singleton client

Create a shared Prisma instance to avoid connection exhaustion during development:

src/lib/server/prisma.ts

import { PrismaClient } from '@prisma/client';

const globalForPrisma = globalThis as unknown as { prisma: PrismaClient };

export const prisma = globalForPrisma.prisma ?? new PrismaClient();

if (process.env.NODE_ENV !== 'production') {
  globalForPrisma.prisma = prisma;
}

Drizzle

Install

Terminal

npx sv create sveltekit-db9
cd sveltekit-db9
npm install drizzle-orm pg
npm install -D drizzle-kit @types/pg

Schema

src/lib/server/schema.ts

import { pgTable, serial, varchar, boolean, timestamp } from 'drizzle-orm/pg-core';

export const todos = pgTable('todos', {
  id: serial('id').primaryKey(),
  title: varchar('title', { length: 500 }).notNull(),
  done: boolean('done').default(false),
  createdAt: timestamp('created_at', { withTimezone: true }).defaultNow(),
});

Singleton client

src/lib/server/db.ts

import { drizzle } from 'drizzle-orm/node-postgres';
import { Pool } from 'pg';

const globalForDb = globalThis as unknown as { pool: Pool };

const pool = globalForDb.pool ?? new Pool({
  connectionString: process.env.DATABASE_URL,
});

if (process.env.NODE_ENV !== 'production') {
  globalForDb.pool = pool;
}

export const db = drizzle(pool);

Push the schema to DB9:

Terminal

npx drizzle-kit push

Server Load Function

SvelteKit load functions run on the server, making them the right place to query DB9.

Prisma

src/routes/todos/+page.server.ts

import { prisma } from '$lib/server/prisma';
import type { PageServerLoad } from './$types';

export const load: PageServerLoad = async () => {
  const todos = await prisma.todo.findMany({
    orderBy: { createdAt: 'desc' },
  });

  return { todos };
};

Drizzle

src/routes/todos/+page.server.ts

import { db } from '$lib/server/db';
import { todos } from '$lib/server/schema';
import { desc } from 'drizzle-orm';
import type { PageServerLoad } from './$types';

export const load: PageServerLoad = async () => {
  const allTodos = await db.select().from(todos).orderBy(desc(todos.createdAt));

  return { todos: allTodos };
};

Form Actions

SvelteKit form actions handle mutations server-side with progressive enhancement.

Prisma

src/routes/todos/+page.server.ts

import { prisma } from '$lib/server/prisma';
import type { Actions, PageServerLoad } from './$types';

export const load: PageServerLoad = async () => {
  const todos = await prisma.todo.findMany({
    orderBy: { createdAt: 'desc' },
  });
  return { todos };
};

export const actions: Actions = {
  create: async ({ request }) => {
    const data = await request.formData();
    await prisma.todo.create({
      data: { title: data.get('title') as string },
    });
  },
  toggle: async ({ request }) => {
    const data = await request.formData();
    const id = Number(data.get('id'));
    const todo = await prisma.todo.findUniqueOrThrow({ where: { id } });
    await prisma.todo.update({
      where: { id },
      data: { done: !todo.done },
    });
  },
};

Drizzle

src/routes/todos/+page.server.ts

import { db } from '$lib/server/db';
import { todos } from '$lib/server/schema';
import { eq, desc, not } from 'drizzle-orm';
import type { Actions, PageServerLoad } from './$types';

export const load: PageServerLoad = async () => {
  const allTodos = await db.select().from(todos).orderBy(desc(todos.createdAt));
  return { todos: allTodos };
};

export const actions: Actions = {
  create: async ({ request }) => {
    const data = await request.formData();
    await db.insert(todos).values({
      title: data.get('title') as string,
    });
  },
  toggle: async ({ request }) => {
    const data = await request.formData();
    const id = Number(data.get('id'));
    await db
      .update(todos)
      .set({ done: not(todos.done) })
      .where(eq(todos.id, id));
  },
};

Production Notes

Never expose the connection string to the client

DB9 connections must happen server-side only (load functions, form actions, API routes). The connection string contains your admin credentials. Place database modules in src/lib/server/ so SvelteKit prevents them from being imported in client code.

• Server-side only: All DB9 queries must run in load functions, form actions, or +server.ts API routes. Files in src/lib/server/ are automatically excluded from client bundles.
• Port 5433: DB9 uses port 5433, not the default PostgreSQL port 5432.
• TLS required: Use sslmode=require in the connection string for DB9’s hosted service.
• Node adapter required: DB9 requires a TCP pgwire connection. Use @sveltejs/adapter-node for deployment — edge adapters (Cloudflare, Vercel Edge) do not support raw TCP sockets.

Install the Node adapter:

Terminal

npm install @sveltejs/adapter-node

svelte.config.js

import adapter from '@sveltejs/adapter-node';
import { vitePreprocess } from '@sveltejs/vite-plugin-svelte';

export default {
  preprocess: vitePreprocess(),
  kit: {
    adapter: adapter(),
  },
};

Troubleshooting

ECONNREFUSED on port 5432

DB9 uses port 5433, not 5432. Verify your DATABASE_URL includes the correct port.

Edge adapter errors

DB9 requires pgwire (TCP), which is not available in edge runtimes. Switch to @sveltejs/adapter-node. Cloudflare and Vercel Edge adapters will not work.

Connection pool exhaustion in development

SvelteKit’s dev server reloads modules on change. Without the singleton pattern shown above, each reload opens a new connection pool. Use the globalThis pattern in src/lib/server/ and restart the dev server to release stale connections.

prisma db push fails

DB9 has limited information_schema support. If prisma db push fails, manage tables with raw SQL. See the Prisma guide for details.

Next Pages

• Prisma — full Prisma integration guide
• Drizzle — full Drizzle integration guide
• Connect — connection strings and authentication
• Production Checklist — deployment readiness