Add subtask position

app/Schema/Postgres.php

@@ -6,7 +6,29 @@ use PDO;
 use Core\Security;
 use Model\Link;
 
-const VERSION = 29;
+const VERSION = 30;
+
+function version_30($pdo)
+{
+    $pdo->exec('ALTER TABLE subtasks ADD COLUMN position INTEGER DEFAULT 1');
+
+    $task_id = 0;
+    $urq = $pdo->prepare('UPDATE subtasks SET position=? WHERE id=?');
+
+    $rq = $pdo->prepare('SELECT * FROM subtasks ORDER BY task_id, id ASC');
+    $rq->execute();
+
+    foreach ($rq->fetchAll(PDO::FETCH_ASSOC) as $subtask) {
+
+        if ($task_id != $subtask['task_id']) {
+            $position = 1;
+            $task_id = $subtask['task_id'];
+        }
+
+        $urq->execute(array($position, $subtask['id']));
+        $position++;
+    }
+}
 
 function version_29($pdo)
 {