one time only one record is active?

Question

Attachment and checkbox is true then show error message record already activated.

I tried this trigger

trigger con on contact (before insert) { 

Boolean active= false; 

    if (Trigger.isBefore) { 


                  email.Adderror('Record already activated'); 
       else active= false; 
            } 
}

Answer 1

Use trigger before insert, before update you can achieve this. You can put SOQL Query also in trigger to check the activated record. If that record exist then you throw error.

Answer 2

Try this piece of code.This will help you.

trigger trig_IsActive on eTMFFolder__c (before insert) { 

Boolean isFirstTime = false; 
Set<string> typeSet = new Set<string>();
    if (Trigger.isBefore) { 

        if (Trigger.isInsert) { 
            for (eTMFFolder__c fol : Trigger.new) { 
               if(fol.isActive__c)
                  typeSet.add(fol.Type__c);
            } 
           List<eTMFFolder__c > folList = [select id from eTMFFolder__c  WHERE Type__c  IN: typeSet];
          if(folList.size() > 0)
                Trigger.new[0].Adderror('Record already activated');
        } 
    } 
}

Answer 3

You can have a before insert trigger which will check the Type__c and isActive__c field if found a single record with the same type and isActive__c equal true then Use addError method.