sql.js-fts5

library1.4.0jsnpmunverified

sql.js is a pure JavaScript SQLite library compiled with Emscripten, allowing SQL database operations directly in the browser or Node.js without native dependencies. Current stable version is 1.11.0 (as of early 2025), with regular releases. It supports full SQLite syntax, prepared statements, transaction support, and exports database as Uint8Array. Unlike native SQLite bindings (e.g., better-sqlite3), sql.js works entirely in memory and requires loading a .wasm file. It is ideal for client-side web apps, offline tools, and scenarios where native modules cannot be used. The library is MIT licensed and community-maintained.

database

npm install sql.js-fts5

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · SQL.JS-FTS5

sql.js-fts5

databasejavascriptv1.4.0

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

initSqlJs

✓ const initSqlJs = require('sql.js');

✗ import initSqlJs from 'sql.js';

Default export is a factory function. ESM import is not supported; use CommonJS or dynamic import.

Database

✓ const db = new SQL.Database();

✗ const db = new Database();

Database is a property of the initialized module, not a standalone export.

Statement

✓ const stmt = db.prepare('SELECT ?');

✗ const stmt = new SQL.Statement(db);

Statement objects are created via Database.prepare(), not directly instantiated.

Shows asynchronous initialization, database creation, prepared statements, and query execution.

const initSqlJs = require('sql.js'); const SQL = await initSqlJs({ locateFile: file => `https://sql.js.org/dist/${file}` }); const db = new SQL.Database(); db.run('CREATE TABLE test (id int, name text)'); db.run('INSERT INTO test VALUES (?,?)', [1, 'hello']); const stmt = db.prepare('SELECT * FROM test'); while (stmt.step()) console.log(stmt.getAsObject()); db.close();

Debug

Known issues

gotchaWASM binary must be loaded separately; locateFile is required in browsers

fix

Provide locateFile in initSqlJs config pointing to the .wasm file, or copy the file from node_modules.

affects: >=1.0.0

gotchaDatabase exists only in memory; changes are lost unless explicitly exported

fix

Call db.export() to get Uint8Array, and save it to disk or localStorage.

affects: >=1.0.0

deprecatedIn-memory only, no direct file write support

fix

For file persistence, use native SQLite bindings like better-sqlite3.

affects: >=1.0.0

gotchaStatement object must be freed manually to avoid memory leaks

fix

Call stmt.free() after use, especially in long-running applications.

affects: >=1.0.0

gotchaThread-safety: not safe to share a Database across Web Workers without cloning

fix

Create separate Database instances per worker or use structured cloning.

affects: >=1.0.0

Errors

Common errors & fixes

TypeError: Cannot read property 'Database' of undefined

Using SQL.Database before initSqlJs resolves

fix

Wait for initSqlJs to complete and pass the module to an async function.

Error: cannot locate the wasm file

locateFile not configured or incorrect path

fix

Provide locateFile option in initSqlJs config pointing to the .wasm file.

Error: Database is closed

Trying to use a database after calling db.close()

fix

Do not reuse closed database; create a new instance if needed.

Upgrade

Version history

1.4.0latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

24 hits · last 30 days

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