better-sqlite3

What is better-sqlite3?

better-sqlite3 is a fast and simple SQLite3 library for Node.js applications. It provides a synchronous API for interacting with SQLite databases, making it easier to write and maintain code. The library is designed to be efficient and easy to use, with a focus on performance and simplicity.

What are better-sqlite3's main functionalities?

Database Connection

This feature allows you to establish a connection to an SQLite database. The `Database` constructor takes the path to the database file as an argument.

const Database = require('better-sqlite3');
const db = new Database('my-database.db');

Executing SQL Statements

This feature allows you to prepare and execute SQL statements. The `prepare` method creates a prepared statement, and the `all` method executes the statement and returns all matching rows.

const stmt = db.prepare('SELECT * FROM users WHERE age > ?');
const users = stmt.all(18);

Inserting Data

This feature allows you to insert data into the database. The `run` method executes the prepared statement with the provided parameters.

const insert = db.prepare('INSERT INTO users (name, age) VALUES (?, ?)');
const info = insert.run('John Doe', 30);

Transaction Management

This feature allows you to manage transactions. The `transaction` method creates a transaction that can execute multiple statements atomically.

const insert = db.prepare('INSERT INTO users (name, age) VALUES (?, ?)');
const insertMany = db.transaction((users) => {
  for (const user of users) insert.run(user.name, user.age);
});
insertMany([{ name: 'Alice', age: 25 }, { name: 'Bob', age: 35 }]);

Custom Functions

This feature allows you to define custom SQL functions. The `function` method registers a new function that can be used in SQL statements.

db.function('add', (a, b) => a + b);
const result = db.prepare('SELECT add(2, 3)').get();

Other packages similar to better-sqlite3

sqlite3

The `sqlite3` package is another popular SQLite library for Node.js. Unlike better-sqlite3, it provides an asynchronous API, which can be beneficial for non-blocking operations. However, it can be more complex to use due to the asynchronous nature of its API.

node-sqlite3

The `node-sqlite3` package is similar to `sqlite3` and provides an asynchronous API for SQLite. It is widely used and well-documented, but like `sqlite3`, it can be more challenging to work with compared to the synchronous API of better-sqlite3.

sql.js

The `sql.js` package is a JavaScript library that runs SQLite in the browser using Emscripten. It is useful for web applications that need to use SQLite in a client-side environment. However, it is not designed for Node.js server-side applications like better-sqlite3.

README

better-sqlite3

The fastest and simplest library for SQLite3 in Node.js.

• Full transaction support
• High performance, efficiency, and safety
• Easy-to-use synchronous API (faster than an asynchronous API... yes, you read that correctly)
• Support for user-defined functions, aggregates, and extensions
• 64-bit integers (invisible until you need them)

How other libraries compare

	select 1 row  get()	select 100 rows   all()	select 100 rows iterate() 1-by-1	insert 1 row run()	insert 100 rows in a transaction
better-sqlite3	1x	1x	1x	1x	1x
sqlite and sqlite3	10.4x slower	2.2x slower	18.8x slower	2.8x slower	12.9x slower

You can verify these results by running the benchmark yourself. Both npm/sqlite and npm/sqlite3 have nearly identical performance because they both use the same engine.

Installation

npm install --save better-sqlite3

If you have trouble installing, check the troubleshooting guide.

Usage

const db = require('better-sqlite3')('foobar.db', options);

const row = db.prepare('SELECT * FROM users WHERE id=?').get(userId);
console.log(row.firstName, row.lastName, row.email);

Why should I use this instead of node-sqlite3?

• node-sqlite3 uses asynchronous APIs for tasks that are either CPU-bound or serialized. That's not only bad design, but it wastes tons of resources. It also causes mutex thrashing which has devastating effects on performance.
• node-sqlite3 exposes low-level (C language) memory management functions. better-sqlite3 does it the JavaScript way, allowing the garbage collector to worry about memory management.
• better-sqlite3 is simpler to use, and it provides nice utilities for some operations that are very difficult or impossible in node-sqlite3.
• better-sqlite3 is much faster than node-sqlite3 in most cases, and just as fast in all other cases.

When is this library not appropriate?

In most cases, if you're attempting something that cannot be reasonably accomplished with better-sqlite3, it probably cannot be reasonably accomplished with SQLite3 in general. For example, if you're executing queries that take one second to complete, and you expect to have many concurrent users executing those queries, no amount of asynchronicity will save you from SQLite3's serialized nature. Fortunately, SQLite3 is very very fast. With proper indexing, we've been able to achieve upward of 2000 queries per second with 5-way-joins in a 60 GB database, where each query was handling 5–50 kilobytes of real data.

If you have a performance problem, the most likely causes are inefficient queries, improper indexing, or a lack of WAL mode—not better-sqlite3 itself. However, there are some cases where better-sqlite3 could be inappropriate:

• If you expect a high volume of concurrent reads each returning many megabytes of data (i.e., videos)
• If you expect a high volume of concurrent writes (i.e., a social media site)
• If your database's size is near the terabyte range

For these situations, you should probably use a full-fledged RDBMS such as PostgreSQL.

Documentation

• API documentation
• Performance (also see benchmark results)
• 64-bit integer support
• SQLite3 compilation

License

MIT