Merge branch 'DBAL-742' into 2.3

lib/Doctrine/DBAL/Schema/OracleSchemaManager.php

@@ -109,10 +109,16 @@ class OracleSchemaManager extends AbstractSchemaManager
             $tableColumn['column_name'] = '';
         }
 
-        if (stripos($tableColumn['data_default'], 'NULL') !== null) {
+        if ($tableColumn['data_default'] === 'NULL') {
             $tableColumn['data_default'] = null;
         }
 
+        if (null !== $tableColumn['data_default']) {
+            // Default values returned from database are enclosed in single quotes.
+            // Sometimes trailing spaces are also encountered.
+            $tableColumn['data_default'] = trim(trim($tableColumn['data_default']), "'");
+        }
+
         $precision = null;
         $scale = null;