Object trigger for checkbox

Question

I'm creating a trigger on the user object which is supposed to do a certain action if a checkbox is checked.

trigger Penalizacion_Memo on User (before update) {
for (user us : trigger.new){
    if (us.MEMO__c==TRUE){

        Decimal Cambio_Porcentual   = -0.2;
        Penalizacion_Porcentual_Logica.Creacion_Tareas_Porcentual(Cambio_Porcentual, us.Id);

    }    
  }
}

My question is if another update is made to the user record and the MEMO checkbox is still checked would that still fire the tigger? I think yes and if so what can I do for it to trigger only when the specific change is made?

Answer 1

You could use the oldMap, but that won't stop it the 2nd time it is unselected, You would need to figure out some different logic if you want that trigger to never fire once Memo is selected

for(ID u : trigger.newMap.keySet())
{
    if(trigger.newMap.get(u).Memo__c && trigger.newMap.get(u).Memo__c != trigger.oldMap.get(u).Memo__c )
    {

    }
}

Answer 2

Please take a look at

Trigger.old
Trigger.oldMap

You can compare record before update (old) and after (new).