Method Query

cassandradriver/executor.go:25–63

Query runs a SELECT, paging by gocql PageState/PageSize, and returns rows with gocql-native types normalized to portable Go values.

(ctx context.Context, stmt Statement)

// Query runs a SELECT, paging by gocql PageState/PageSize, and returns rows with
// gocql-native types normalized to portable Go values.
func (e *gocqlExecutor) Query(ctx context.Context, stmt Statement) (ResultSet, error) {
	q := e.session.Query(stmt.CQL, stmt.Args...).WithContext(ctx).Idempotent(stmt.Idempotent)
	if stmt.PageSize > 0 {
		q = q.PageSize(stmt.PageSize)
	}
	if len(stmt.PageState) > 0 {
		q = q.PageState(stmt.PageState)
	}
	iter := q.Iter()

	var rows []map[string]any
	if stmt.PageSize > 0 {
		// Read exactly the current page. Calling MapScan past NumRows would make
		// gocql transparently fetch the next page, defeating cursor pagination.
		n := iter.NumRows()
		for i := 0; i < n; i++ {
			raw := make(map[string]any)
			if !iter.MapScan(raw) {
				break
			}
			rows = append(rows, normalizeRow(raw))
		}
	} else {
		for {
			raw := make(map[string]any)
			if !iter.MapScan(raw) {
				break
			}
			rows = append(rows, normalizeRow(raw))
		}
	}
	next := iter.PageState()
	if err := iter.Close(); err != nil {
		return ResultSet{}, fmt.Errorf("cassandradriver: query failed: %w", err)
	}
	page := make([]byte, len(next))
	copy(page, next) // gocql reuses its buffer; copy before it's recycled
	return ResultSet{Rows: rows, PageState: page}, nil
}

// Exec runs a write. The applied/page state of an LWT is not surfaced in v1.
func (e *gocqlExecutor) Exec(ctx context.Context, stmt Statement) (ResultSet, error) {