Introdução ao Rust e MongoDB

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cargo new --bin rust_quickstart

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[dependencies]
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mongodb = "2.1"
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bson = { version = "2", features = ["chrono-0_4"] } # Needed for using chrono datetime in doc
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tokio = "1"
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chrono = "0.4" # Used for setting DateTimes
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serde = "1" # Used in the Map Data into Structs section

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cargo run

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use mongodb::{Client, options::{ClientOptions, ResolverConfig}};
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use std::env;
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use std::error::Error;
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use tokio;
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#[tokio::main]
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async fn main() -> Result<(), Box<dyn Error>> {
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   // Load the MongoDB connection string from an environment variable:
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   let client_uri =
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      env::var("MONGODB_URI").expect("You must set the MONGODB_URI environment var!");
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   // A Client is needed to connect to MongoDB:
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   // An extra line of code to work around a DNS issue on Windows:
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   let options =
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      ClientOptions::parse_with_resolver_config(&client_uri, ResolverConfig::cloudflare())
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         .await?;
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   let client = Client::with_options(options)?;
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   // Print the databases in our MongoDB cluster:
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   println!("Databases:");
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   for name in client.list_database_names(None, None).await? {
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      println!("- {}", name);
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   }
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   Ok(())
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}

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# Unix (including MacOS):
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export MONGODB_URI='mongodb+srv://yourusername:yourpasswordgoeshere@rustquickstart-123ab.mongodb.net/test?retryWrites=true&w=majority'
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# Windows CMD shell:
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set MONGODB_URI='mongodb+srv://yourusername:yourpasswordgoeshere@rustquickstart-123ab.mongodb.net/test?retryWrites=true&w=majority'
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# Powershell:
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$Env:MONGODB_URI='mongodb+srv://yourusername:yourpasswordgoeshere@rustquickstart-123ab.mongodb.net/test?retryWrites=true&w=majority'

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$ cargo run
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   Compiling rust_quickstart v0.0.1 (/Users/judy2k/development/rust_quickstart)
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   Finished dev [unoptimized + debuginfo] target(s) in 3.35s
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   Running `target/debug/rust_quickstart`
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Databases:
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- sample_airbnb
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- sample_analytics
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- sample_geospatial
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- sample_mflix
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- sample_supplies
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- sample_training
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- sample_weatherdata
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- admin
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- local

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use chrono::{TimeZone, Utc};
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use mongodb::bson::doc;
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let new_doc = doc! {
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   "title": "Parasite",
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   "year": 2020,
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   "plot": "A poor family, the Kims, con their way into becoming the servants of a rich family, the Parks. But their easy life gets complicated when their deception is threatened with exposure.",
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   "released": Utc.ymd(2020, 2, 7).and_hms(0, 0, 0),
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};

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{ title: "Parasite", year: 2020, plot: "A poor family, the Kims, con their way into becoming the servants of a rich family, the Parks. But their easy life gets complicated when their deception is threatened with exposure.", released: Date("2020-02-07 00:00:00 UTC") }

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// Get the 'movies' collection from the 'sample_mflix' database:
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let movies = client.database("sample_mflix").collection("movies");

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let insert_result = movies.insert_one(new_doc.clone(), None).await?;
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println!("New document ID: {}", insert_result.inserted_id);

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New document ID: ObjectId("5e835f3000415b720028b0ad")

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// Look up one document:
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let movie: Document = movies
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   .find_one(
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      doc! {
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            "title": "Parasite"
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      },
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      None,
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   ).await?
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   .expect("Missing 'Parasite' document.");
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println!("Movie: {}", movie);

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Movie: { _id: ObjectId("5e835f3000415b720028b0ad"), title: "Parasite", year: 2020, plot: "A poor family, the Kims, con their way into becoming the servants of a rich family, the Parks. But their easy life gets complicated when their deception is threatened with exposure.", released: Date("2020-02-07 00:00:00 UTC") }

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// Update the document:
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let update_result = movies.update_one(
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   doc! {
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      "_id": &movie.get("_id")
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   },
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   doc! {
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      "$set": { "year": 2019 }
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   },
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   None,
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).await?;
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println!("Updated {} document", update_result.modified_count);

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// Look up the document again to confirm it's been updated:
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let movie = movies
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   .find_one(
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      doc! {
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            "_id": &movie.get("_id")
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      },
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      None,
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   ).await?
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   .expect("Missing 'Parasite' document.");
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println!("Updated Movie: {}", &movie);

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Updated 1 document
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Updated Movie: { _id: ObjectId("5e835f3000415b720028b0ad"), title: "Parasite", year: 2019, plot: "A poor family, the Kims, con their way into becoming the servants of a rich family, the Parks. But their easy life gets complicated when their deception is threatened with exposure.", released: Date("2020-02-07 00:00:00 UTC") }

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// Delete all documents for movies called "Parasite":
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let delete_result = movies.delete_many(
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   doc! {
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      "title": "Parasite"
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   },
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   None,
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).await?;
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println!("Deleted {} documents", delete_result.deleted_count);

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use serde::{Deserialize, Serialize};
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use mongodb::bson::{Bson, oid::ObjectId};
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// Working with Document can be verbose:
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if let Ok(title) = new_doc.get_str("title") {
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   println!("title: {}", title);
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} else {
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   println!("no title found");
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}

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// You use `serde` to create structs which can serialize & deserialize between BSON:
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#[derive(Serialize, Deserialize, Debug)]
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struct Movie {
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   #[serde(rename = "_id", skip_serializing_if = "Option::is_none")]
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   id: Option<ObjectId>,
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   title: String,
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   year: i32,
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   plot: String,
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   #[serde(with = "bson::serde_helpers::chrono_datetime_as_bson_datetime")]
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   released: chrono::DateTime<Utc>,
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}

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// Initialize struct to be inserted:
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let captain_marvel = Movie {
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   id: None,
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   title: "Captain Marvel".to_owned(),
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   year: 2019,
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};
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// Convert `captain_marvel` to a Bson instance:
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let serialized_movie = bson::to_bson(&captain_marvel)?;
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let document = serialized_movie.as_document().unwrap();
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// Insert into the collection and extract the inserted_id value:
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let insert_result = movies.insert_one(document.to_owned(), None).await?;
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let captain_marvel_id = insert_result
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   .inserted_id
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   .as_object_id()
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   .expect("Retrieved _id should have been of type ObjectId");
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println!("Captain Marvel document ID: {:?}", captain_marvel_id);

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Captain Marvel document ID: ObjectId(5e835f30007760020028b0ae)

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// Retrieve Captain Marvel from the database, into a Movie struct:
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// Read the document from the movies collection:
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let loaded_movie = movies
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   .find_one(Some(doc! { "_id":  captain_marvel_id.clone() }), None)
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   .await?
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   .expect("Document not found");
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// Deserialize the document into a Movie instance
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let loaded_movie_struct: Movie = bson::from_bson(Bson::Document(loaded_movie))?;
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println!("Movie loaded from collection: {:?}", loaded_movie_struct);

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Movie loaded from collection: Movie { id: Some(ObjectId(5e835f30007760020028b0ae)), title: "Captain Marvel", year: 2019 }

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[dependencies]
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async-std = "1"
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mongodb = { version = "2.1", default-features = false, features = ["async-std-runtime"] }

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use async_std;
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#[async_std::main]
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async fn main() -> Result<(), Box<dyn Error>> {
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   // Your code goes here.
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}

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[dependencies]
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mongodb = { version = "2.1", default-features = false, features = ["sync"] }

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use mongodb::sync::Client;
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// Use mongodb::sync::Client, instead of mongodb::Client:
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let client = Client::with_uri_str(client_uri.as_ref())?;
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// .insert_one().await? becomes .insert_one()?
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let insert_result = movies.insert_one(new_doc.clone(), None)?;