QueryIterator()

Creates an iterator that retrieves query results in bounded batches.

pub async fn query_iterator(&self, request: QueryIteratorRequest) -> Result<QueryIterator>

Request Syntax

let request = QueryIteratorRequest::builder()
    .query(
        QueryRequest::builder()
            .collection_name("books")
            .filter("id > 0")
            .output_fields(["id", "title"])
            .build()?,
    )
    .batch_size(100)
    .build()?;
let mut iterator = client.query_iterator(request).await?;

REQUEST FIELDS:

• query: QueryRequest

  The QueryRequest that defines the collection, filter, and output fields. Query iterators do not accept primary-key IDs or order_by_fields. Required.

• batch_size: usize

  Number of rows returned per next() call. Defaults to 1000.

• reduce_stop_for_best: bool

  Whether the iterator stops fetching a page as soon as the best result is found. Defaults to true.

• cursor: Option<QueryCursor>

  A resumable primary-key cursor that pins the MVCC snapshot and resumes pagination from the captured position. Resume only with a cursor obtained from QueryIterator::cursor.

RETURNS:

Result

Returns a QueryIterator. Call next() to receive the next QueryResponse batch (None when exhausted) and close() when done. Returns Error on failure.

Example

let request = QueryIteratorRequest::builder()
    .query(
        QueryRequest::builder()
            .collection_name("books")
            .filter("id > 0")
            .output_fields(["id", "title"])
            .build()?,
    )
    .batch_size(100)
    .build()?;
let mut iterator = client.query_iterator(request).await?;
while let Some(batch) = iterator.next().await? {
    println!("got {} rows", batch.results().get_row_count());
}