SQLite client for JavaScript.

See sqlitempi.com for a general overview.

Install

• yarn add sqlite-mpi-client-js
  • Or: npm install --save sqlite-mpi-client-js

IO Providers

You also need to install an IO provider.

• React Native
• Node.js

Usage

See ./test/all for detailed usage.

Get a file ref

// Note: Example is for Node.js.
const {smpi} = require("sqlite-mpi-client-js");
const iop = require("smpi-iop-node-ffi");

const c = smpi.newClient(iop);
const f = c.newFileRef("/tmp/db-file.sqlite");

Write transactions

• There is only one active write transaction at a time per SQLite file.

  • This applies at an OS level, for all processes.

• Write tx requests will queue when there is an active outstanding write tx.

  • Queued write tx requests will resolve in First In First Out (FIFO) manner.
  • When the promise returned from f.getWriteTx() resolves, the wtx is active.

const wtx = await f.getWriteTx();

// `q` can be a read or write with write txs.
await wtx.q("SELECT 1+1");

await wtx.read("SELECT 1+1");

await wtx.write("INSERT ...");

await wtx.commit();
// await wtx.rollback();

Read transactions

• Read transactions are concurrent; you can have many read transactions active and reading from the same database file.

const rtx = await f.getReadTx();

// `q` must be a read.
await rtx.q("SELECT 1+1");

await rtx.read("SELECT 1+1");

// No writes.
// await tx.write("INSERT ...");

await rtx.commit();
// await rtx.rollback();

Params

const wtx = await f.getWriteTx();

// Index based.
await wtx.write("INSERT INTO t1 (b) VALUES (?), (?)", [1, 2]);
await wtx.write("INSERT INTO t1 (b) VALUES (?1), (?2)", [3, 4]);

// Key based.
await wtx.write("INSERT INTO t1 (b) VALUES (:x), (:y)", {x: 1, y: 2});
await wtx.write("INSERT INTO t1 (b) VALUES (@x), (@y)", {x: 1, y: 2});
await wtx.commit();

Notes

• SQLite WAL mode is always on; you can not turn it off.
• Reads are concurrent, writes queue.