sqlite-wasm-wasi

sqlite-wasm-wasi

Use SQLite from WASM WASI. See parent.

API is similar to better-sqlite3.

Example

Full sources. Also lock.host-wasm-js.

import { open } from 'sqlite-wasm-wasi'

const db = open('/app/example.js.db')
db.exec('drop table if exists example')
db.exec('create table example (id integer, name text, note text, ratio real, big_int integer)')

let insert = db.prepare('insert into example (id, name, note, ratio, big_int) values (?, ?, ?, ?, ?)')
let info = insert.run([1, 'hello from js', null, 3.25, 9007199254740993n])
console.log(info.changes, '== 1')
console.log(info.lastInsertRowid, '== 1')

info = insert.run([2, 'hello from js', null, 3.25, 9007199254740993n])
console.log(info.changes, '== 1')
console.log(info.lastInsertRowid, '== 2')

let select = db.prepare('select id, name, note, ratio, big_int from example where id = ?')
let row = select.one([1])
console.log(row) // >> { id: 1n, name: 'hello from js', note: null, ratio: 3.25, big_int: 9007199254740993n }

select = db.prepare('select * from example where 1 = ? order by id')
let rows = select.all([1])
console.log(rows) // >> [ ..., ... ]

// transactions
db.exec('drop table if exists txn')
db.exec('create table txn (id integer)')
insert = db.prepare('insert into txn (id) values (?)')
let insertMany = db.transaction((nums) => {
  for (const num of nums) { insert.run([num]) }
})

const nums = [1, 4, 5, 6]
insertMany(nums)

select = db.prepare('select * from txn order by id')
rows = select.all()
console.log(rows) // { id: 1n }, { id: 4n }, { id: 5n }, { id: 6n }
db.close()

Linking

You need component.wasm.

If you want to build component.wasm yourself, see: parent.

Otherwise get component.wasm from node_modules/sqlite-wasm-wasi/dist/ after npm install sqlite-wasm-wasi.

You need also dist/wit/sqlite.wit. Look at justfile and all will become clear.

Notes

let stmt = db.prepare('sql') returns a "prepared statement".

Prepared statements can be run 1 or 100 or more times.

If your app is eg an HTTP server you need to be calling stmt.release() when done with it.

Rust has the Drop trait and does not need release.

Notes

open() detaults to "unix-dotfile" VFS.

Unix-dotfile VFS is exactly like default "unix" except it avoids POSIX flock() system calls.

Lock.host will be forking and trying to upstream wasmtime flock support.

License

[e-mail]

MIT