diff --git modules/field/modules/field_sql_storage/field_sql_storage.module modules/field/modules/field_sql_storage/field_sql_storage.module
index 9f85a10..522d816 100644
--- modules/field/modules/field_sql_storage/field_sql_storage.module
+++ modules/field/modules/field_sql_storage/field_sql_storage.module
@@ -677,9 +677,13 @@ function field_sql_storage_field_storage_purge_field($field) {
  */
 function field_sql_storage_field_storage_details($field) {
   $details = array();
+  $columns = array();
+  $field += array(
+    'columns' => array(),
+  );
 
   // Add field columns.
-  foreach ((array) $field['columns'] as $column_name => $attributes) {
+  foreach ($field['columns'] as $column_name => $attributes) {
     $real_name = _field_sql_storage_columnname($field['field_name'], $column_name);
     $columns[$column_name] = $real_name;
   }
diff --git modules/field/tests/field_test.storage.inc modules/field/tests/field_test.storage.inc
index a86b785..d9a35cd 100644
--- modules/field/tests/field_test.storage.inc
+++ modules/field/tests/field_test.storage.inc
@@ -28,10 +28,13 @@ function field_test_field_storage_info() {
  */
 function field_test_field_storage_details($field) {
   $details = array();
+  $columns = array();
+  $field += array(
+    'columns' => array(),
+  );
 
   // Add field columns.
-  $columns = array();
-  foreach ((array) $field['columns'] as $column_name => $attributes) {
+  foreach ($field['columns'] as $column_name => $attributes) {
     $columns[$column_name] = $column_name;
   }
   return array(
@@ -48,11 +51,14 @@ function field_test_field_storage_details($field) {
  * @see FieldAttachStorageTestCase::testFieldStorageDetailsAlter()
  */
 function field_test_field_storage_details_alter(&$details, $field) {
+  $columns = array();
+  $field += array(
+    'columns' => array(),
+  );
 
   // For testing, storage details are changed only because of the field name.
   if ($field['field_name'] == 'field_test_change_my_details') {
-    $columns = array();
-    foreach ((array) $field['columns'] as $column_name => $attributes) {
+    foreach ($field['columns'] as $column_name => $attributes) {
       $columns[$column_name] = $column_name;
     }
     $details['drupal_variables'] = array(