withClient

withClient<T>(pool: pg.Pool, fn: (client: pg.PoolClient) => Promise<T>): Promise<T>

Check out one connection from the pool, run the callback, then release it — even if the callback throws. Returns whatever the callback returns.

import connect, { withClient } from '@smplcty/db';

const pool = connect();

const rows = await withClient(pool, async (client) => {
  const { rows } = await client.query('select 1 as n');
  return rows;
});

Why it matters

Every query inside fn runs on the same physical connection, so session state (SET LOCAL, set_config, custom GUCs) and transaction state apply consistently across the body. Two separate pool.query(...) calls may land on different connections and lose that relationship.

Note

withClient runs no transaction. If you need BEGIN/COMMIT, use withTransaction. The connection is released with whatever session state the callback left on it — prefer SET LOCAL inside a transaction over SET SESSION.