From 09d9e5011c5fc0eda9d4892cba365969c88084d2 Mon Sep 17 00:00:00 2001
From: Silas Oettinghaus <silas.oettinghaus@email.uni-kiel.de>
Date: Thu, 10 Jul 2025 13:32:25 +0200
Subject: [PATCH] re-attempt DB fetch connection

---
 Classes/DataBaseHandler/DBHandler.m | 26 ++++++++++++++++++++++----
 1 file changed, 22 insertions(+), 4 deletions(-)

diff --git a/Classes/DataBaseHandler/DBHandler.m b/Classes/DataBaseHandler/DBHandler.m
index 73a4321..7e2105a 100644
--- a/Classes/DataBaseHandler/DBHandler.m
+++ b/Classes/DataBaseHandler/DBHandler.m
@@ -43,8 +43,8 @@ classdef DBHandler < handle
                 elseif options.type == "mysql"
 
                     % datasource = "jdbc:mysql://134.245.243.254:3306/labor";
-                    
-                    
+
+
 
                     obj.conn  = database( ...
                         string(obj.dataBase), ...                            % Database name
@@ -578,10 +578,28 @@ classdef DBHandler < handle
             execute(obj.conn, query);
         end
 
-        function answer = fetch(obj,query)
-            answer = fetch(obj.conn,query);
+
+        function answer = fetch(obj, query)
+            maxFast = 20; maxSlow = 30;
+            for attempt = 1:maxSlow
+                try
+                    answer = fetch(obj.conn, query);
+                    return
+                catch ME
+                    if attempt < maxFast
+                        pause(1)
+                    else
+                        pause(10)
+                    end
+                    lastErr = ME;
+                end
+            end
+            pause(60)
+            error('Database fetch failed after %d attempts:\n%s', maxSlow, lastErr.getReport())
         end
 
+
+
         function [result,query] = queryDB(obj, filterParams, selectedFields)
             % getPathsWithFlexibleFilter Retrieves values from Runs table with flexible filtering
             % and lets the user select which fields to include in the SELECT statement.