Struct polodb_core::Database

pub struct Database { /* private fields */ }

API wrapper for Rust-level

Use open API to open a database. A main database file will be generated in the path user provided.

When you own an instance of a Database, the instance holds a file descriptor of the database file. When the Database instance is dropped, the handle of the file will be released.

Collection

A Collection is a dataset of a kind of data. You can use create_collection to create a data collection. To obtain an exist collection, use collection,

Transaction

You an manually start a transaction by 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;
use polodb_core::bson::{Document, doc};

let db = Database::open_file(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();

Implementations

impl Database

pub fn set_log(v: bool)

pub fn get_version() -> String

Return the version of package version in string. Defined in Cargo.toml.

pub fn open_memory() -> DbResult<Database>

pub fn open_memory_with_config(config: Config) -> DbResult<Database>

pub fn open_file<P: AsRef<Path>>(path: P) -> DbResult<Database>

pub fn open_file_with_config<P: AsRef<Path>>(
    path: P,
    config: Config
) -> DbResult<Database>

pub fn create_collection<T: Serialize>(&self, name: &str) -> DbResult<()>

Creates a new collection in the database with the given name.

pub fn collection<T: Serialize>(&self, col_name: &str) -> Collection<'_, T>

Return an exist collection. If the collection is not exists, a new collection will be created.

pub fn start_transaction(&self, ty: Option<TransactionType>) -> DbResult<()>

Manually start a transaction. There are three types of transaction.

• None: Auto transaction
• Some(Transaction::Write): Write transaction
• Some(Transaction::Read): Read transaction

When you pass None to type parameter. The PoloDB will go into auto mode. The PoloDB will go into read mode firstly, once the users execute write operations(insert/update/delete), the DB will turn into write mode.

pub fn commit(&self) -> DbResult<()>

pub fn rollback(&self) -> DbResult<()>

pub fn dump(&self) -> DbResult<FullDump>

pub fn list_collection_names(&self) -> DbResult<Vec<String>>

Gets the names of the collections in the database.

pub fn handle_request<R: Read>(
    &self,
    pipe_in: &mut R
) -> DbResult<HandleRequestResult>

pub fn find_one<T: DeserializeOwned>(
    &self,
    col_name: &str,
    filter: impl Into<Option<Document>>
) -> DbResult<Option<T>>