Attach databases

Use db.attach() to query another database file through an existing connection. Its alias becomes a SQLite schema name, which distinguishes its tables from those in the main database. Use it when one query needs data from both files.

Attach and query a database

In NitroSQLite, call attach() on an open connection. The alias becomes the SQLite schema name. Use the same platform root and relative location convention as open().

import { open } from 'react-native-nitro-sqlite'

const db = open({ name: 'app.sqlite' })

db.attach('archive.sqlite', 'archive', 'databases')

const { results } = db.execute(
  `SELECT main.notes.id, archive.history.note
   FROM main.notes
   JOIN archive.history ON archive.history.note_id = main.notes.id`,
)

db.detach('archive')
db.close()

File paths and aliases

The example assumes the tables and files already exist. SQLite can create the attached file when it is missing, so verify the intended path when opening prepopulated data. attach() and detach() are synchronous connection operations; they fail while the connection queue is busy. A failed attach or detach throws NitroSQLiteError through the connection wrapper.

Only pass database names, locations, and aliases you control. The library does not bind these as parameters. Query values still belong in ? parameters. See database lifecycle for the location convention and the generated NitroSQLiteConnection reference for signatures.