Complex Query Parsing

Complex query parsing enables NestJS applications to handle nested objects and arrays in URL query strings, going beyond simple key-value pairs.

Examples

?filter[where][name]=John&filter[where][age]=30
?item[]=1&item[]=2

Configuration

Express

Use the extended query parser:

const app = await NestFactory.create<NestExpressApplication>(AppModule);
app.set('query parser', 'extended');

Fastify

Configure a custom querystringParser with the qs library:

import { FastifyAdapter } from '@nestjs/platform-fastify';
import qs from 'qs';
 
const app = await NestFactory.create(
  AppModule,
  new FastifyAdapter({
    querystringParser: (str) => qs.parse(str),
  }),
);

Installation

For Fastify, install the querystring parser:

npm install qs