More focused Apex Trigger: Before Delete

Question

I'm new to the world of Apex and have managed to cobble together this code that looks at a particular field and prevents deletion of that record if a particular field (in this case 'Data Source' isn't empty/null.

Although the code below works, it will prevent deletion if the field has any value in it and I need to customise it so that if a particular word is in that field, only then will it block deletion. But when I tried to specify this using code like "IBIS" (the name of an internal system I'm targetting), I got errors about incorrect data type.

Is what I'm trying to achieve possible?

My trigger code:

trigger IBISAccountDeleteTrigger on Account (before delete) {
    for(Account acc : trigger.old){
        if(acc.Data_Source__c != null)
            acc.adderror('Sorry, we cannot delete this record as it came from IBIS.');
        }
    }

Data_Source__c is a Text field btw.

Thanks in advance :-)

Answer 1

//You can use the following

 for(Account acc : trigger.old){
        if(acc.Data_Source__c != null && acc.Data_Source__c.contains('IBIS')){
            acc.adderror('Sorry, we cannot delete this record as it came from IBIS.');
        }
 }

//if caps does not matter you can use the containsIgnoreCase(substring)

Refer to https://developer.salesforce.com/docs/atlas.en-us.234.0.apexref.meta/apexref/apex_methods_system_string.htm