--- /dev/null
+<?php
+
+namespace Drupal\rdf\Plugin\migrate\source\d7;
+
+use Drupal\migrate\Row;
+use Drupal\migrate_drupal\Plugin\migrate\source\DrupalSqlBase;
+
+/**
+ * Drupal 7 rdf source from database.
+ *
+ * @MigrateSource(
+ * id = "d7_rdf_mapping",
+ * source_module = "rdf"
+ * )
+ */
+class RdfMapping extends DrupalSqlBase {
+
+ /**
+ * {@inheritdoc}
+ */
+ public function query() {
+ return $this->select('rdf_mapping', 'r')->fields('r');
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function prepareRow(Row $row) {
+ $field_mappings = [];
+ foreach (unserialize($row->getSourceProperty('mapping')) as $field => $mapping) {
+ if ($field === 'rdftype') {
+ $row->setSourceProperty('types', $mapping);
+ }
+ else {
+ $field_mappings[$field] = $mapping;
+ }
+ }
+ $row->setSourceProperty('fieldMappings', $field_mappings);
+
+ return parent::prepareRow($row);
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function fields() {
+ return [
+ 'type' => $this->t('The name of the entity type a mapping applies to (node, user, comment, etc.'),
+ 'bundle' => $this->t('The name of the bundle a mapping applies to.'),
+ 'mapping' => $this->t('The serialized mapping of the bundle type and fields to RDF terms.'),
+ 'types' => $this->t('RDF types.'),
+ 'fieldMappings' => $this->t('RDF field mappings.'),
+ ];
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getIds() {
+ return [
+ 'type' => [
+ 'type' => 'string',
+ ],
+ 'bundle' => [
+ 'type' => 'string',
+ ],
+ ];
+ }
+
+}