Struct PoolGuard 

pub struct PoolGuard { /* private fields */ }

A borrowed connection from the pool. Returns to the pool on drop.

If the connection is in a failed transaction state, broken, or marked for discard, it is dropped (decrements open_count) instead of returned.

Implementations

impl PoolGuard

pub fn mark_discard(&mut self)

Mark this connection for discard — it will NOT be returned to the pool on drop. The open_count is decremented and the TCP connection is closed.

pub fn cancel(&self) -> Result<(), DriverError>

Cancel the currently running query on the underlying connection.

Opens a new TCP connection and sends a CancelRequest to PG. The cancel connection is closed immediately after.

pub fn pid(&self) -> i32

Get the backend process ID for this connection.

Panics

Panics if the connection has already been returned to the pool (Drop ran). This cannot happen in safe code because PoolGuard owns the connection.

pub fn is_idle(&self) -> bool

Whether the connection is idle (not in a transaction).

Panics

Panics if the connection has already been returned to the pool (Drop ran). This cannot happen in safe code because PoolGuard owns the connection.

pub fn is_in_transaction(&self) -> bool

Whether the connection is inside a transaction.

Panics

Panics if the connection has already been returned to the pool (Drop ran). This cannot happen in safe code because PoolGuard owns the connection.

pub fn query( &mut self, sql: &str, sql_hash: u64, params: &[&(dyn Encode + Sync)], ) -> Result<QueryResult, DriverError>

Execute a prepared query and return rows.

pub fn execute( &mut self, sql: &str, sql_hash: u64, params: &[&(dyn Encode + Sync)], ) -> Result<u64, DriverError>

Execute a query without result rows (INSERT/UPDATE/DELETE).

pub fn execute_pipeline( &mut self, sql: &str, sql_hash: u64, param_sets: &[&[&(dyn Encode + Sync)]], ) -> Result<Vec<u64>, DriverError>

Execute the same statement N times with different params in one pipeline.

Sends all N Bind+Execute messages + one Sync. One round-trip for N operations. Returns the affected row count for each parameter set.

pub fn simple_query(&mut self, sql: &str) -> Result<(), DriverError>

Execute a simple (unprepared) query.

pub fn simple_query_rows( &mut self, sql: &str, ) -> Result<Vec<SimpleRow>, DriverError>

Execute a simple query and return rows as text.

Uses PostgreSQL’s simple query protocol — all values are strings.

pub fn for_each<F>( &mut self, sql: &str, sql_hash: u64, params: &[&(dyn Encode + Sync)], f: F, ) -> Result<(), DriverError>

where F: FnMut(PgDataRow<'_>) -> Result<(), DriverError>,

Process each row via a closure with zero-copy PgDataRow.

pub fn for_each_raw<F>( &mut self, sql: &str, sql_hash: u64, params: &[&(dyn Encode + Sync)], f: F, ) -> Result<(), DriverError>

where F: FnMut(&[u8]) -> Result<(), DriverError>,

Process each DataRow as raw bytes — fastest path.

pub fn query_streaming_start( &mut self, sql: &str, sql_hash: u64, params: &[&(dyn Encode + Sync)], chunk_size: i32, ) -> Result<(Arc<[ColumnDesc]>, bool), DriverError>

Start a streaming query.

pub fn streaming_send_execute( &mut self, chunk_size: i32, ) -> Result<(), DriverError>

Send Execute+Flush for a streaming query (2nd+ chunks).

pub fn streaming_next_chunk( &mut self, arena: &mut Arena, all_col_offsets: &mut Vec<(usize, i32)>, ) -> Result<bool, DriverError>

Read the next chunk of rows from an in-progress streaming query.

pub fn copy_in<'a, I>( &mut self, table: &str, columns: &[&str], rows: I, ) -> Result<u64, DriverError>

where I: IntoIterator<Item = &'a str>,

Bulk copy data INTO a table from an iterator of text rows.

Each row is a tab-separated string (TSV format). Returns the row count.

pub fn copy_out<W: Write>( &mut self, query: &str, writer: &mut W, ) -> Result<u64, DriverError>

Bulk copy data OUT of a table/query to a writer.

Writes TSV-formatted rows. Returns the row count.

pub fn is_sync(&self) -> bool

Whether this guard holds a sync connection.

Trait Implementations

impl Drop for PoolGuard

fn drop(&mut self)

Executes the destructor for this type.