Struct AsyncRowset 

pub struct AsyncRowset<'conn> { /* private fields */ }

A streaming result set returned from an async query.

See Rowset for the sync equivalent and the full memory-behavior contract — both use constant-memory chunked iteration.

Implementations

impl<'conn> AsyncRowset<'conn>

pub fn schema(&self) -> Option<ResultSchema>

Returns the schema (column metadata) for the result set.

For TCP this returns None until the first chunk has been fetched (the RowDescription is the first message of the stream). For Arrow it is available immediately.

pub async fn next_chunk(&mut self) -> Result<Option<Vec<Row>>>

Returns the next chunk of rows, or None when the stream is exhausted.

Errors

• Returns crate::Error::Client if the server sends an ErrorResponse while streaming the result set.
• Returns crate::Error::Io on transport-level I/O failures.
• Returns crate::Error::Other if an Arrow IPC chunk cannot be decoded.

pub async fn collect_rows(self) -> Result<Vec<Row>>

Collects every remaining row into a Vec. Consumes the rowset.

Errors

Returns the first error produced by next_chunk while draining the stream.

pub async fn collect_column<T: RowValue>(self) -> Result<Vec<Option<T>>>

Collects the first column of every row, preserving NULL as None.

Errors

Returns the first error produced by next_chunk. SQL NULL cells yield Option::None entries, not errors.

pub async fn collect_column_non_null<T: RowValue>(self) -> Result<Vec<T>>

Collects the first column of every row, dropping NULLs.

Errors

Returns the first error produced by collect_column.

pub async fn first_row(self) -> Result<Option<Row>>

Returns the first row of the result set, or None if the result is empty. Consumes the rowset.

Errors

Returns the error from next_chunk. An empty result yields Ok(None).

pub async fn require_first_row(self) -> Result<Row>

Returns the first row, or an error if the result set is empty.

Errors

• Returns the error from first_row.
• Returns crate::Error::Other with message "Query returned no rows" if the result set is empty.

pub async fn scalar<T: RowValue>(self) -> Result<Option<T>>

Returns the first column of the first row as Option<T>, or an error if the result set is empty.

Errors

Returns the error from require_first_row. SQL NULL in the single cell yields Ok(None).

pub async fn require_scalar<T: RowValue>(self) -> Result<T>

Returns the first column of the first row as T, or an error if the result set is empty or the value is NULL.

Errors

• Returns the error from scalar.
• Returns crate::Error::Other with message "Scalar query returned NULL" if the single cell is SQL NULL.

Trait Implementations

impl Debug for AsyncRowset<'_>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.