Apex触发器可自动填充多个记录的查找字段

Question

I am trying to update a lookup field(Benefit_ID in Customer object) with the below code, The code works fine for single record but it is failing for multiple records:

Error: "caused by: System.DmlException: Insert failed. First exception on row 0; first error: CANNOT_INSERT_UPDATE_ACTIVATE_ENTITY, "

trigger updatelookupfield_Customer on Customer__c (before insert,before update) {
    Set<String> Bundle = new Set<String>();

    for (Customer__c Cust : Trigger.new) {
        Bundle.add(Cust.Bundle__c);
    }
List<Benfit__c> BenfitList = [SELECT id, Bundle__c FROM Benfit__c WHERE Bundle__c IN :Bundle];

    Map<String, Benfit__c> shippingNumToContactMap = new Map<String, Benfit__c>();

    for (Benfit__c c : BenfitList) {
        shippingNumToContactMap.put(c.Bundle__c, c);
    }

    for (Customer__c o : Trigger.new) {
              if (o.Bundle__c != null) {
            o.Benefit_ID__c = shippingNumToContactMap.get(o.Bundle__c).id;
        }
        else {
            o.Benefit_ID__c = null;
        }
    }
    }

Answer 1

it seems that issue will be on line o.Benefit_ID__c = shippingNumToContactMap.get(o.Bundle__c).id; you are trying to get a value from a map with a key, but you are not checking if the key is present in the map.

try to add check that the key is in the map before trying to get a value for it.

trigger updatelookupfield_Customer on Customer__c (before insert,before update) {
Set<String> Bundle = new Set<String>();

for (Customer__c Cust : Trigger.new) {
    Bundle.add(Cust.Bundle__c);
}
List<Benfit__c> BenfitList = [SELECT id, Bundle__c FROM Benfit__c WHERE Bundle__c IN :Bundle];

Map<String, Benfit__c> shippingNumToContactMap = new Map<String, Benfit__c>();

for (Benfit__c c : BenfitList) {
    shippingNumToContactMap.put(c.Bundle__c, c);
}

for (Customer__c o : Trigger.new) {
          if (o.Bundle__c != null && shippingNumToContactMap.containsKey(o.Bundle__c)) {
        o.Benefit_ID__c = shippingNumToContactMap.get(o.Bundle__c).id;
    }
    else {
        o.Benefit_ID__c = null;
    }
}
}

Svata

Answer 2

It doesn't seem to me as though you actually need any Apex here.

So there's a Text field on Customer called Bundle__c.

You also have a custom object called Benfit__c which also has a string field called Bundle__c.

You're using the Bundle__c field on Customer to work out which Benfit__c applies to them.

Why can't you have a straight lookup from Customer to Benfit__c?