improve migration class

enums/Aggregation.php

@@ -0,0 +1,21 @@
+<?php
+namespace DatabaseHelper\enums;
+
+enum Aggregation
+{
+    case COUNT;
+    case SUM;
+    case AVG;
+    case MIN;
+    case MAX;
+
+    public function toString(): string {
+        return match ($this) {
+            self::COUNT => 'COUNT',
+            self::SUM => 'SUM',
+            self::AVG => 'AVG',
+            self::MIN => 'MIN',
+            self::MAX => 'MAX',
+        };
+    }
+}