Mastering Fuzzy Search: A Step-by-Step Guide Using PostgreSQL and Kysely

Are you looking to implement typo-tolerant search functionality within your web application? If so, you’re not alone. Many developers face the challenge of enabling flexible search capabilities that can handle misspellings or slight variations in user queries.

In this comprehensive tutorial, we’ll explore how to perform a basic “fuzzy” search utilizing PostgreSQL’s powerful full-text search features in combination with Kysely, a modern TypeScript SQL query builder. Whether you’re using PostgreSQL for your database or considering an upgrade, this guide will walk you through the process with practical, interactive examples.

Why Fuzzy Search Matters

Fuzzy search techniques allow your application to retrieve relevant results even when the user input contains typos or slight mismatches. Implementing such functionality enhances user experience, increases search accuracy, and makes your application more robust.

Setting Up an Interactive Environment

To demonstrate the concepts effectively, this tutorial uses PGlite, a tool that runs PostgreSQL in your browser. This setup provides an instant, interactive environment for practicing SQL queries without the need for local database installation.

Step-by-Step Implementation

1. Prepare Your Database with Sample Data

Start by creating a sample dataset that we’ll search through. Here’s an example schema and some sample entries:

“`sql
CREATE TABLE products (
id SERIAL PRIMARY KEY,
name TEXT,
description TEXT
);

INSERT INTO products (name, description) VALUES
(‘Apple iPhone’, ‘Smartphone with cutting-edge features’),
(‘Samsung Galaxy’, ‘Android smartphone with high specs’),
(‘Google Pixel’, ‘Pure Android experience’),
(‘OnePlus Nord’, ‘Affordable high-performance phone’);
“`

2. Enable Fuzzy Search Capabilities

PostgreSQL offers the pg_trgm extension, which enables trigram-based similarity searches:

sql
CREATE EXTENSION IF NOT EXISTS pg_trgm;

This extension allows us to compare string similarity efficiently.

3. Craft a Fuzzy Search Query

Using Kysely, you can build parameterized queries to perform fuzzy searches. Here is a conceptual example in TypeScript:

“`typescript
import { Kysely, sql } from ‘kysely’;

async function searchProducts(query: string, db: Kysely) {
const results = await db
.selectFrom(‘