Struct Pipeline 

pub struct Pipeline<'a> { /* private fields */ }

Pipeline mode for batching multiple queries.

Created by Conn::pipeline.

Implementations

impl<'a> Pipeline<'a>

pub fn exec<'s, P: ToParams>( &mut self, statement: &'s (impl IntoStatement + ?Sized), params: P, ) -> Result<Ticket<'s>>

Queue a statement execution.

The statement can be either:

• A &PreparedStatement returned from conn.prepare() or conn.prepare_batch()
• A raw SQL &str for one-shot execution

This method only buffers the command locally - no network I/O occurs until sync() or flush() is called.

Example

let stmt = conn.prepare("SELECT id, name FROM users WHERE id = $1")?;

let (r1, r2) = conn.pipeline(|p| {
    let t1 = p.exec(&stmt, (1,))?;
    let t2 = p.exec("SELECT COUNT(*) FROM users", ())?;
    p.sync()?;

    let r1: Vec<(i32, String)> = p.claim_collect(t1)?;
    let r2: Option<(i64,)> = p.claim_one(t2)?;
    Ok((r1, r2))
})?;

pub fn flush(&mut self) -> Result<()>

Send a FLUSH message to trigger server response.

This forces the server to send all pending responses without establishing a transaction boundary. Called automatically by claim methods when needed.

pub fn sync(&mut self) -> Result<()>

Send a SYNC message to establish a transaction boundary.

After calling sync, you must claim all queued operations in order. The ReadyForQuery message will be consumed automatically after claiming.

pub fn claim_collect<T: for<'b> FromRow<'b>>( &mut self, ticket: Ticket<'_>, ) -> Result<Vec<T>>

Claim and collect all rows.

Results must be claimed in the same order they were queued.

pub fn claim_one<T: for<'b> FromRow<'b>>( &mut self, ticket: Ticket<'_>, ) -> Result<Option<T>>

Claim and return just the first row.

Results must be claimed in the same order they were queued.

pub fn claim_drop(&mut self, ticket: Ticket<'_>) -> Result<()>

Claim and discard all rows.

Results must be claimed in the same order they were queued.

pub fn pending_count(&self) -> usize

Returns the number of operations that have been queued but not yet claimed.

pub fn is_aborted(&self) -> bool

Returns true if the pipeline is in aborted state due to an error.