diff --git a/core/lib/Drupal/Core/Entity/FieldableDatabaseStorageController.php b/core/lib/Drupal/Core/Entity/FieldableDatabaseStorageController.php
index 9af998b..370dea6 100644
--- a/core/lib/Drupal/Core/Entity/FieldableDatabaseStorageController.php
+++ b/core/lib/Drupal/Core/Entity/FieldableDatabaseStorageController.php
@@ -281,15 +281,19 @@ protected function mapFromStorageRecords(array $records, $load_revision = FALSE)
     $entities = array();
     foreach ($records as $id => $record) {
       $entities[$id] = array();
+      // Skip the item delta and item value levels but let the field assign
+      // the value as suiting. This avoids unnecessary array hierarchies and
+      // saves memory here.
       foreach ($record as $name => $value) {
-        // Skip the item delta and item value levels but let the field assign
-        // the value as suiting. This avoids unnecessary array hierarchies and
-        // saves memory here.
+        // Handle columns named [field_name]__[column_name] (e.g for field types
+        // that store several properties).
         if ($field = strstr($name, '__', TRUE)) {
           $property_name = substr($name, strpos($name, '__') + 2);
           $entities[$id][$field][Language::LANGCODE_DEFAULT][$property_name] = $value;
         }
         else {
+          // Handle columns named directly after the field (e.g if the field
+          // type only stores one property).
           $entities[$id][$name][Language::LANGCODE_DEFAULT] = $value;
         }
       }
@@ -338,13 +342,13 @@ protected function attachPropertyData(array &$entities, $revision_id = FALSE) {
       }
 
       $data = $query->execute();
-      $field_definition = \Drupal::entityManager()->getFieldDefinitions($this->entityType);
+      $field_definitions = \Drupal::entityManager()->getFieldDefinitions($this->entityType);
       $translations = array();
       if ($this->revisionDataTable) {
-        $data_fields = array_flip(array_diff(drupal_schema_fields_sql($this->entityInfo['revision_data_table']), drupal_schema_fields_sql($this->entityInfo['base_table'])));
+        $data_column_names = array_flip(array_diff(drupal_schema_fields_sql($this->entityInfo['revision_data_table']), drupal_schema_fields_sql($this->entityInfo['base_table'])));
       }
       else {
-        $data_fields = array_flip(drupal_schema_fields_sql($this->entityInfo['data_table']));
+        $data_column_names = array_flip(drupal_schema_fields_sql($this->entityInfo['data_table']));
       }
 
       foreach ($data as $values) {
@@ -355,15 +359,19 @@ protected function attachPropertyData(array &$entities, $revision_id = FALSE) {
         $langcode = empty($values['default_langcode']) ? $values['langcode'] : Language::LANGCODE_DEFAULT;
         $translations[$id][$langcode] = TRUE;
 
-        foreach ($field_definition as $name => $definition) {
-          if (isset($data_fields[$name])) {
-            $entities[$id][$name][$langcode] = $values[$name];
+        foreach (array_keys($field_definitions) as $field_name) {
+          // Handle columns named directly after the field.
+          if (isset($data_column_names[$field_name])) {
+            $entities[$id][$field_name][$langcode] = $values[$field_name];
           }
           else {
-            foreach ($data_fields as $data_field) {
-              if (($field = strstr($data_field, '__', TRUE)) && $field === $name) {
-                $property_name = substr($data_field, strpos($data_field, '__') + 2);
-                $entities[$id][$name][$langcode][$property_name] = $values[$data_field];
+            foreach ($data_column_names as $data_column_name) {
+              // Handle columns named [field_name]__[column_name], for which we
+              // need to look through all column names from the table that start
+              // with the name of the field.
+              if (($field = strstr($data_column_name, '__', TRUE)) && $field === $field_name) {
+                $property_name = substr($data_column_name, strpos($data_column_name, '__') + 2);
+                $entities[$id][$field_name][$langcode][$property_name] = $values[$data_column_name];
               }
             }
           }
@@ -774,9 +782,13 @@ protected function mapToStorageRecord(EntityInterface $entity, $table_key = 'bas
       $values[$name] = isset($definitions[$name]) && isset($entity->$name->value) ? $entity->$name->value : NULL;
     }
 
+    // Handle fields that store multiple properties and match each property name
+    // to its schema column name.
     foreach (array_keys($multi_column_fields) as $field_name) {
       $field_items = $entity->get($field_name);
       $field_value = $field_items->getValue();
+      // @todo Reconsider the usage of getFieldPropertyNames() after
+      // https://drupal.org/node/2144327.
       foreach ($field_items->getFieldDefinition()->getFieldPropertyNames() as $property_name) {
         if (isset($schema['fields'][$field_name . '__' . $property_name])) {
           $values[$field_name . '__' . $property_name] = isset($field_value[0][$property_name]) ? $field_value[0][$property_name] : NULL;