How to create a wrapper for db with tenant_id to always be added to where clause?

[bluepuma77]

Hi community,

I would like to use Drizzle for a multi-tenant DB running with regular NodeJS server.

Is it possible to automagically add a where clause to all query functions?

Bonus: also add an additional field to all insert and update functions?

// imaginary pseudo code for Drizzle with SvelteKit

// create Drizzle `db` object
const client = postgres(env.DATABASE_URL)
const db = drizzle(client, { schema })

// function called for every incoming request
export async function handle({ event, resolve }) {

    // regular query for session using main `db` object
    const session = await db.query.sessions.findFirst({
        where: eq(sessions.id, event.cookies.get('sessionId')
    })

    if (session) {
        // create some kind of wrapper around `db` object with current context `tenant_id` and `username`
        const tenandDb = dbWrapper(db, session.tenant_id, session.username)
    
        // wrapper query, will automagically add "where tenant_id = tenant_id" to query from context
        const items = await tenandDb.query.items.findMany()

        // wrapper insert, will automagically add values "tenant_id: tenant_id" and "created_by: username" from context
        await tenandDb.insert(schema.items).values({ name: 'something' })
    }  
}

Are there best practices to implement something like this in 2025? Chatbots going crazy, but delivered nothing useful.

Note 1: currently not looking into RLS, as the database might change to something different than Postgres.

Note 2: this has been discussed here a year ago, without a real solution (discussion), maybe something changed?

Note 3: potentially relevant discussion about middleware (discussion)