Mixup in MySQL Querrys

Hey guys,

I hope my Thread title is not too much misleading. So. My issue is that the MySQL Querrys are getting mixed up if there are multiple people interacting with it at the same time/short timeframe

What do I mean?

They have an Inventory Menu showing them some Items. If they click one of them the Program makes a MySQL querry and printing out the result. [Works]

However what I came across yesterday is that when multiple people are using it at the same time or at a very short timeframe it somehow mixes up and Player A gets his result. Player B gets Player A's result.

So what I am doing is [narrowed quite a bit down but it is the same]

Code:java

@EventHandler
public void onItemClick(InventoryClickEvent e) {
if(e.getCurrentItem().getType().equals(Material.WOOL)) {
Player p = (Player) e.getWhoClicked();
p.sendMessage(String.valueOf(getInt(p, "wool")));
}
}
 
 
public int getInt(Player p, String selection) {
// here all the stuff to get the Integer from the MySQL Database
// works perfectly fine if only one player at the time over a timeframe
}

So. Anyone has an Idea on how I can do it so it basicly always gets the right result?
Was thinking of creating one big multidimensional Array at the start, as soon as the player joins add him in there with all the current value. But will most likely cause the same issue if multiple people join at once

 

If the issue is multiple people accessing it, then just "synchronized" the method.

Although it really shouldn't be an issue with multiple people accessing it. What is the code for getInt()?

Also running an individual query for each person is inefficient, when you could simply do it in one query.

 

simply use the keyword "synchronized"

 

Louis1234567890987654321 1Rogue

Will test it with the synchronized, thanks

and for the code

Code:java

Statement statement = conntection.createStatement();
ResultSet rs = statement.executeQuery("SELECT `" +selection"` FROM `TestTable` WHERE `player`='"
+ p.getName() + "'");
if(!(rs.next())) {
return 0;
}
return rs.getInt(1);

 

If all of this is happening on the same thread, adding synchronized won't do anything.

 

I wonder, where else are you accessing the connection variable?

It would also help if you provide an actual error.

 

I am not getting any error. I just get the value from the wrong person. And thats the only time

 

Database connections should be ok with concurrency by nature, and as others have mentioned you're probably single-threaded so "synchronized" isn't going to do anything.

Can we see your full code? It's possible there's a logic issues elsewhere that is getting the data mixed up.