From 28c0a199ae0051d9f0451ae22d6decbef76a02d5 Mon Sep 17 00:00:00 2001
From: Martin Ambrus <martin@martinambrus.com>
Date: Mon, 28 Aug 2017 22:05:16 +0200
Subject: [PATCH] fix: SQL optimization

---
 GameEngine/Database.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/GameEngine/Database.php b/GameEngine/Database.php
index 89b0cf6a..4a56b477 100755
--- a/GameEngine/Database.php
+++ b/GameEngine/Database.php
@@ -2995,7 +2995,7 @@ class MYSQLi_DB {
 	}
 
 	function getTrainingList() {
-		$q = "SELECT * FROM " . TB_PREFIX . "training where vref != ''";
+		$q = "SELECT * FROM " . TB_PREFIX . "training where vref IS NOT NULL";
 		$result = mysqli_query($this->dblink,$q);
 		return $this->mysqli_fetch_all($result);
 	}