Query: Actix Web Documentation

# Query Extractor

The web::Query extractor is used to process the URL query string. Actix Web integrates seamlessly with Serde to deserialize query parameters into typed structs.

#Handling Defaults and Options

Because web requests are unpredictable, missing query parameters can cause extraction to fail. To handle this gracefully, use Option<T> or implement Serde default values.

code_blocksrust

use serde::Deserialize;

#[derive(Deserialize)]
struct Pagination {
    #[serde(default = "default_page")]
    page: u32,
    limit: Option<u32>,
}

fn default_page() -> u32 { 1 }

If page is omitted from the URL, it will default to 1. If limit is omitted, it will be None.

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Reference Implementation

The following code snippet demonstrates the authoritative pattern for this documentation.

src/main.rs

Edition 2024

1use actix_web::{web, App, HttpServer, Responder};
2use serde::Deserialize;
3 
4#[derive(Deserialize)]
5struct Search {
6    term: String,
7}
8 
9async fn search(q: web::Query<Search>) -> impl Responder {
10    format!("Search results for: {}", q.term)
11}
12 
13#[actix_web::main]
14async fn main() -> std::io::Result<()> {
15    HttpServer::new(|| {
16        App::new().route("/search", web::get().to(search))
17    })
18    .bind(("127.0.0.1", 8080))?
19    .run()
20    .await
21}

Query

#Handling Defaults and Options

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Reference Implementation

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