Struct Database 

pub struct Database { /* private fields */ }

The application’s handle on the database.

Registered as application state, so a handler reaches it with req.state::<Database>().

Implementations

impl Database

pub async fn connect(url: &str) -> Result<Database>

Connect using a URL: postgres://user:password@host:port/database.

pub async fn with_config(config: DatabaseConfig) -> Result<Database>

Connect using explicit settings, verifying the connection works.

pub fn lazy(config: DatabaseConfig) -> Result<Database>

Build a handle without touching the network. Useful when the process should start even if the database is briefly down.

pub fn with_driver(driver: Arc<dyn Driver>) -> Database

Use a driver directly — how a database this crate does not know about would be plugged in.

pub fn dialect(&self) -> &dyn Dialect

What SQL this connection speaks.

The query and schema builders take it, which is how one builder produces correct SQL for three different databases.

pub fn pool(&self) -> &Pool

pub fn table(&self, name: &str) -> QueryBuilder

Start a query: db.table("users").filter("active", true).get(&db).await.

pub async fn select(&self, sql: &str, params: &[Value]) -> Result<Vec<Row>>

Run a query and return every row.

pub async fn select_one( &self, sql: &str, params: &[Value], ) -> Result<Option<Row>>

Run a query expecting at most one row.

pub async fn execute(&self, sql: &str, params: &[Value]) -> Result<u64>

Run a statement and return the number of rows it affected.

pub async fn run(&self, sql: &str) -> Result<u64>

Run one or more statements with no parameters — DDL, mostly.

pub async fn insert_returning_key( &self, sql: &str, params: &[Value], column: &str, ) -> Result<Option<Value>>

Run an insert and hand back the key the database generated.

Three mechanisms, one method: PostgreSQL returns a row from RETURNING, SQL Server from OUTPUT, and MySQL reports the id in the packet that acknowledges the insert, with no row at all.

pub async fn scalar<T: FromValue>( &self, sql: &str, params: &[Value], ) -> Result<Option<T>>

Read a single value from the first column of the first row.

pub async fn begin(&self) -> Result<Transaction>

Begin a transaction.

Rust’s borrow rules make Laravel’s DB::transaction(closure) shape awkward — the closure’s future would have to borrow the connection it was handed — so the transaction is a value you hold instead:

let mut tx = db.begin().await?;
tx.execute("update accounts set balance = balance - $1", &[amount]).await?;
tx.commit().await?;

Dropping it without committing rolls back, so an early ? cannot leave a half-finished transaction behind.

pub async fn close(&self)

Close every pooled connection.

Trait Implementations

impl Clone for Database

fn clone(&self) -> Database

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.