NamedPortal

Struct NamedPortal 

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pub struct NamedPortal<'tx> { /* private fields */ }
Expand description

Handle to a named portal for async iterative row fetching.

Created by [Transaction::exec_portal()]. Use execute() to retrieve rows in batches. The lifetime parameter ties the portal to the transaction that created it, preventing the transaction from being committed/rolled back while the portal is alive.

§Example

conn.tx(|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?;

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impl<'tx> NamedPortal<'tx>

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pub fn name(&self) -> &str

Get the portal name.

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pub fn is_complete(&self) -> bool

Check if portal execution is complete (no more rows available).

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pub async fn execute<H: BinaryHandler>( &mut self, conn: &mut Conn, max_rows: u32, handler: &mut H, ) -> Result<()>

Execute the portal with a handler.

Fetches up to max_rows rows. Pass 0 to fetch all remaining rows. Updates internal completion status.

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pub async fn execute_collect<T: for<'a> FromRow<'a>>( &mut self, conn: &mut Conn, max_rows: u32, ) -> Result<Vec<T>>

Execute the portal and collect typed rows.

Fetches up to max_rows rows. Pass 0 to fetch all remaining rows.

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

Close the portal and sync.

This sends Close(Portal) followed by Sync to end the transaction.

Auto Trait Implementations§

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impl<'tx> Freeze for NamedPortal<'tx>

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impl<'tx> RefUnwindSafe for NamedPortal<'tx>

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impl<'tx> Send for NamedPortal<'tx>

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impl<'tx> Sync for NamedPortal<'tx>

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impl<'tx> Unpin for NamedPortal<'tx>

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impl<'tx> UnwindSafe for NamedPortal<'tx>

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impl<T> Any for T
where T: 'static + ?Sized,

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Gets the TypeId of self. Read more
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where T: ?Sized,

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impl<T> BorrowMut<T> for T
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fn borrow_mut(&mut self) -> &mut T

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impl<T> From<T> for T

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fn from(t: T) -> T

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where U: From<T>,

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Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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type Output = T

Should always be Self
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type Error = Infallible

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