Struct Transaction 

pub struct Transaction { /* private fields */ }

A PostgreSQL transaction for the asynchronous connection.

This struct provides transaction control. The connection is passed to commit and rollback methods to execute the transaction commands.

Implementations

impl Transaction

pub async fn commit(self, conn: &mut Conn) -> Result<()>

Commit the transaction.

This consumes the transaction and sends a COMMIT statement to the server. The connection must be passed as an argument to execute the commit.

Errors

Returns Error::InvalidUsage if the connection is not the same as the one that started the transaction.

pub async fn rollback(self, conn: &mut Conn) -> Result<()>

Rollback the transaction.

This consumes the transaction and sends a ROLLBACK statement to the server. The connection must be passed as an argument to execute the rollback.

Errors

Returns Error::InvalidUsage if the connection is not the same as the one that started the transaction.

pub async fn exec_portal<S: IntoStatement, P: ToParams>( &self, conn: &mut Conn, statement: S, params: P, ) -> Result<NamedPortal<'_>>

Create a named portal for iterative row fetching within this transaction.

Named portals are safe to use within an explicit transaction because SYNC messages do not destroy them (only COMMIT/ROLLBACK does).

The statement can be either:

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

Example

conn.transaction(|conn, tx| async move {
    let mut portal = tx.exec_portal(conn, &stmt, ()).await?;

    while !portal.is_complete() {
        let rows: Vec<(i32,)> = portal.execute_collect(conn, 100).await?;
        process(rows);
    }

    portal.close(conn).await?;
    tx.commit(conn).await
}).await?;

Errors

Returns Error::InvalidUsage if the connection is not the same as the one that started the transaction.