Expand description
PoloDB is an embedded JSON-based database.
PoloDB is a library written in Rust that implements a lightweight MongoDB. PoloDB has no dependency(except for libc), so it can be easily run on most platform(thanks for Rust Language). The data of PoloDB is stored in a file. The file format is stable, cross-platform, and backwards compaitible. The API of PoloDB is very similar to MongoDB. It’s very easy to learn and use.
§Usage
The Database
structure provides all the API to get access to the DB file.
§Open a local file
use polodb_core::Database;
let db = Database::open_path(db_path).unwrap();
§Example
use polodb_core::{Database, CollectionT};
use serde::{Serialize, Deserialize};
#[derive(Debug, Serialize, Deserialize)]
struct Book {
title: String,
author: String,
}
let db = Database::open_path(db_path).unwrap();
let collection = db.collection("books");
collection.insert_one(Book {
title: "The Three-Body Problem".to_string(),
author: "Liu Cixin".to_string(),
}).unwrap();
§Inserting documents into a collection
use polodb_core::{Database, CollectionT};
use polodb_core::bson::{Document, doc};
let db = Database::open_path(db_path).unwrap();
let collection = db.collection::<Document>("books");
let docs = vec![
doc! { "title": "1984", "author": "George Orwell" },
doc! { "title": "Animal Farm", "author": "George Orwell" },
doc! { "title": "The Great Gatsby", "author": "F. Scott Fitzgerald" },
];
collection.insert_many(docs).unwrap();
§Finding documents in a collection
use polodb_core::{Database, CollectionT};
use polodb_core::bson::{Document, doc};
use serde::{Deserialize, Serialize};
#[derive(Debug, Serialize, Deserialize)]
struct Book {
title: String,
author: String,
}
let db = Database::open_path(db_path).unwrap();
let collection = db.collection::<Book>("books");
let docs = vec![
Book { title: "1984".to_string(), author: "George Orwell".to_string() },
Book { title: "Animal Farm".to_string(), author: "George Orwell".to_string() },
Book { title: "The Great Gatsby".to_string(), author: "F. Scott Fitzgerald".to_string() },
];
collection.insert_many(docs).unwrap();
let books = collection.find(doc! {}).run().unwrap();
for book in books {
println!("name: {:?}", book);
}
§Transactions
A Transaction
is a set of operations that are executed as a single unit.
You an manually start a transaction by Database::start_transaction
method.
If you don’t start it manually, a transaction will be automatically started
in your every operation.
§Example
use polodb_core::{Database, CollectionT};
use polodb_core::bson::{Document, doc};
let db = Database::open_path(db_path).unwrap();
let txn = db.start_transaction().unwrap();
let collection = txn.collection::<Document>("books");
let docs = vec![
doc! { "title": "1984", "author": "George Orwell" },
doc! { "title": "Animal Farm", "author": "George Orwell" },
doc! { "title": "The Great Gatsby", "author": "F. Scott Fitzgerald" },
];
collection.insert_many(docs).unwrap();
txn.commit().unwrap();
Re-exports§
pub extern crate bson;
Modules§
Macros§
Structs§
- A
ClientCursor
is used get the result of a query. You can move the cursor forward using theadvance()
. - A wrapper of collection in struct.
- Config builder for the database
- API wrapper for Rust-level