Struct PgBackend 

pub struct PgBackend { /* private fields */ }

PostgreSQL adapter executing compiled plans on a connection pool.

Implementations

impl PgBackend

pub async fn connect(url: &str) -> Result<Self, BackendError>

Connect to url (postgres://user:pass@host/db) with a pool of up to ten connections, each set to the UTC time zone.

A connection is not checked when it is taken from the pool: SQLx’s test_before_acquire costs a round trip per query. The price is that the first query on a connection the server has closed (a restart, an idle timeout) fails with a connection error instead of being retried on a fresh connection. To have connections checked, use connect_with with PgPoolOptions::new().test_before_acquire(true).

Errors

BackendError::Connection if the pool cannot be created.

pub async fn connect_with( url: &str, options: PgPoolOptions, ) -> Result<Self, BackendError>

Connect with pool settings and mandatory adapter initialization.

Replaces any after_connect callback already stored in options. SQLx does not expose that callback for chaining; pass custom setup to Self::connect_with_init instead. Other pool options are retained.

Args: url: Database URL. options: Pool capacity, timeouts and checkout policy.

Returns: Adapter whose fresh sessions receive mandatory initialization.

Errors

Connection or initialization failure within the acquire deadline.

pub async fn connect_with_init( url: &str, options: PgPoolOptions, init: ConnectionInit<Postgres>, ) -> Result<Self, BackendError>

Compose explicit custom setup with mandatory session settings.

Args: url: Database URL. options: Pool settings; its stored after_connect is replaced. init: Custom hook run first on every new/reconnected session.

Returns: Adapter after custom setup and required settings succeed.

Errors

Connection or initialization failure within the acquire deadline.

pub fn from_pool(pool: PgPool) -> Self

Wrap an existing pool. Its connections should use the UTC time zone (see the module docs).

Trait Implementations

impl Backend for PgBackend

fn read_parameter_count( &self, plan: &QueryPlan, ) -> Result<Option<usize>, OrmError>

Count compiled read parameters without database I/O.

fn begin<'life0, 'async_trait>( &'life0 self, isolation: Option<IsolationLevel>, ) -> Pin<Box<dyn Future<Output = Result<Box<dyn Transaction>, OrmError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,

Begin a transaction on a dedicated connection.

fn begin_schema<'life0, 'async_trait>( &'life0 self, transactional: bool, ) -> Pin<Box<dyn Future<Output = Result<Box<dyn Transaction>, OrmError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,

Connection for a schema migration.

impl Clone for PgBackend

fn clone(&self) -> PgBackend

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PgBackend

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Executor for PgBackend

fn capabilities(&self) -> BackendCapabilities

Declared capabilities.

fn fetch<'life0, 'life1, 'async_trait>( &'life0 self, plan: &'life1 QueryPlan, ) -> Pin<Box<dyn Future<Output = Result<QueryResult, OrmError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Execute a read plan.

fn execute<'life0, 'life1, 'async_trait>( &'life0 self, plan: &'life1 WritePlan, ) -> Pin<Box<dyn Future<Output = Result<ExecResult, OrmError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Execute a write plan.

fn fetch_raw<'life0, 'life1, 'async_trait>( &'life0 self, sql: &'life1 str, params: Vec<Value>, ) -> Pin<Box<dyn Future<Output = Result<QueryResult, OrmError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Run raw SQL returning rows. params are bound, never interpolated.

fn execute_raw<'life0, 'life1, 'async_trait>( &'life0 self, sql: &'life1 str, params: Vec<Value>, ) -> Pin<Box<dyn Future<Output = Result<u64, OrmError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Run raw SQL returning the affected-row count. params are bound.

fn execute_script<'life0, 'life1, 'async_trait>( &'life0 self, sql: &'life1 str, ) -> Pin<Box<dyn Future<Output = Result<(), OrmError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Run a multi-statement script without parameters (DDL, migrations).