if(SQL SELECT) { do something; } ????

I need to do an action based on a mySQL SELECT result… for example if result = 1 do something and change register to 0. If result = 0, do another thing and change register to 1.
The thing is that multiple people will using the game, so, how can I be sure that, between the time I did the sql query and the time I do the action and change the value, someone else hasn’t modified the value already?

EDIT: Javascript language :wink:
EDIT 2: This is solved only with transactions? the first query is a select and the second one is an update.

I hope you program in C# ^^

private UnityEngine.Object queueLock = new UnityEngine.Object();

public void ...(..)  {
  if (something) {
    lock (queueLock){
      //critical action (like setting a global variable)

this should put you on the right track :slight_smile:

This is actually not a Unity question, but here is a suggestion for solving your problem anyway.
This is a common problem which is solved by using transactions. Google “mysql transaction”. Your problem is similar to a problem of withdrawing money from account, which is often used in transaction examples.