Struct CopyOut 

#[non_exhaustive]
pub struct CopyOut<'a> { /* private fields */ }

A reader for a COPY OUT operation.

Created via Connection::copy_out. Data is received from the server in chunks.

Implementations

impl<'a> CopyOut<'a>

pub fn format(&self) -> u8

The overall format code for this COPY operation.

0 = text, 1 = binary.

pub fn column_formats(&self) -> &[u16]

Per-column format codes.

pub async fn read_next(&mut self) -> Result<Option<Vec<u8>>>

Read the next chunk of COPY data.

Returns None when the server has finished sending data.

pub async fn read_all(&mut self) -> Result<Vec<u8>>

Read all remaining COPY data into a single buffer.

pub async fn for_each<F>(&mut self, f: F) -> Result<()>

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

Process each chunk with a callback (streaming).

pub async fn for_each_row<F>(&mut self, f: F) -> Result<()>

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

Process each text-format row with a callback.

This is a convenience method for text-format COPY OUT operations. It collects all data, splits by newlines, and calls f for each row’s tab-separated fields.

Example

let mut copy = conn.copy_out("COPY users TO STDOUT").await?;
copy.for_each_row(|fields| {
    println!("id={}, name={}", fields[0], fields[1]);
    Ok(())
}).await?;

pub async fn for_each_csv_row<F>( &mut self, delimiter: char, quote: char, f: F, ) -> Result<()>

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

Process each CSV-format row with a callback.

This is a convenience method for CSV-format COPY OUT operations. It collects all data, splits by newlines, and parses each row as a simple CSV line (handling quoted fields with the specified delimiter and quote character).

Example

let mut copy = conn.copy_out("COPY users TO STDOUT WITH (FORMAT csv)").await?;
copy.for_each_csv_row(',', '"', |fields| {
    println!("id={}, name={}", fields[0], fields[1]);
    Ok(())
}).await?;

Trait Implementations

impl<'a> Drop for CopyOut<'a>

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.