--- /dev/null
+<?php
+
+namespace Drupal\file\Plugin\migrate\source\d6;
+
+use Drupal\migrate\Row;
+use Drupal\migrate_drupal\Plugin\migrate\source\DrupalSqlBase;
+
+/**
+ * Drupal 6 upload source from database.
+ *
+ * @MigrateSource(
+ * id = "d6_upload",
+ * source_provider = "upload"
+ * )
+ */
+class Upload extends DrupalSqlBase {
+
+ /**
+ * The join options between the node and the upload table.
+ */
+ const JOIN = 'n.nid = u.nid AND n.vid = u.vid';
+
+ /**
+ * {@inheritdoc}
+ */
+ public function query() {
+ $query = $this->select('upload', 'u')
+ ->distinct()
+ ->fields('u', ['nid', 'vid']);
+ $query->innerJoin('node', 'n', static::JOIN);
+ $query->addField('n', 'type');
+ return $query;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function prepareRow(Row $row) {
+ $query = $this->select('upload', 'u')
+ ->fields('u', ['fid', 'description', 'list'])
+ ->condition('u.nid', $row->getSourceProperty('nid'))
+ ->orderBy('u.weight');
+ $query->innerJoin('node', 'n', static::JOIN);
+ $row->setSourceProperty('upload', $query->execute()->fetchAll());
+ return parent::prepareRow($row);
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function fields() {
+ return [
+ 'fid' => $this->t('The file Id.'),
+ 'nid' => $this->t('The node Id.'),
+ 'vid' => $this->t('The version Id.'),
+ 'type' => $this->t('The node type'),
+ 'description' => $this->t('The file description.'),
+ 'list' => $this->t('Whether the list should be visible on the node page.'),
+ 'weight' => $this->t('The file weight.'),
+ ];
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getIds() {
+ $ids['vid']['type'] = 'integer';
+ $ids['vid']['alias'] = 'u';
+ return $ids;
+ }
+
+}