--- /dev/null
+<?php
+
+namespace Drupal\taxonomy\Plugin\migrate\source;
+
+use Drupal\migrate\Row;
+use Drupal\migrate_drupal\Plugin\migrate\source\DrupalSqlBase;
+
+/**
+ * Taxonomy term source from database.
+ *
+ * @todo Support term_relation, term_synonym table if possible.
+ *
+ * @MigrateSource(
+ * id = "taxonomy_term",
+ * source_provider = "taxonomy"
+ * )
+ *
+ * @deprecated in Drupal 8.3.0, intended to be removed in Drupal 9.0.0.
+ * Use \Drupal\taxonomy\Plugin\migrate\source\d6\Term or
+ * \Drupal\taxonomy\Plugin\migrate\source\d7\Term.
+ *
+ * @see https://www.drupal.org/node/2879193
+ */
+class Term extends DrupalSqlBase {
+
+ /**
+ * Name of the term data table.
+ *
+ * @var string
+ */
+ protected $termDataTable;
+
+ /**
+ * Name of the term hierarchy table.
+ *
+ * @var string
+ */
+ protected $termHierarchyTable;
+
+ /**
+ * {@inheritdoc}
+ */
+ public function query() {
+ if ($this->getModuleSchemaVersion('taxonomy') >= 7000) {
+ $this->termDataTable = 'taxonomy_term_data';
+ $this->termHierarchyTable = 'taxonomy_term_hierarchy';
+ }
+ else {
+ $this->termDataTable = 'term_data';
+ $this->termHierarchyTable = 'term_hierarchy';
+ }
+
+ $query = $this->select($this->termDataTable, 'td')
+ ->fields('td')
+ ->distinct()
+ ->orderBy('td.tid');
+
+ if (isset($this->configuration['vocabulary'])) {
+ $query->condition('td.vid', (array) $this->configuration['vocabulary'], 'IN');
+ }
+
+ return $query;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function fields() {
+ $fields = [
+ 'tid' => $this->t('The term ID.'),
+ 'vid' => $this->t('Existing term VID'),
+ 'name' => $this->t('The name of the term.'),
+ 'description' => $this->t('The term description.'),
+ 'weight' => $this->t('Weight'),
+ 'parent' => $this->t("The Drupal term IDs of the term's parents."),
+ ];
+ if ($this->getModuleSchemaVersion('taxonomy') >= 7000) {
+ $fields['format'] = $this->t('Format of the term description.');
+ }
+ return $fields;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function prepareRow(Row $row) {
+ // Find parents for this row.
+ $parents = $this->select($this->termHierarchyTable, 'th')
+ ->fields('th', ['parent', 'tid'])
+ ->condition('tid', $row->getSourceProperty('tid'))
+ ->execute()
+ ->fetchCol();
+ $row->setSourceProperty('parent', $parents);
+
+ return parent::prepareRow($row);
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getIds() {
+ $ids['tid']['type'] = 'integer';
+ return $ids;
+ }
+
+}