Blog - USEFUL APEX DELETE BATCH

Utility_Batch_Delete.java

global class Utility_Batch_Delete implements Database.Batchable<SObject>
{
    private String q;
    private String fq;
    private String[] qs;
    
    global Utility_Batch_Delete(String query)
    {
        q = query;
    }
    
    global Utility_Batch_Delete(String query, String finalQuery)
    {
        q = query;
        fq = finalQuery;
    }
    
    global Utility_Batch_Delete(String[] queryList, String finalQuery)
    {
        q = queryList.get(0); 
        queryList.remove(0);
        
        qs = queryList;
        fq = finalQuery;
    }
    
    global Database.QueryLocator start(Database.BatchableContext info)
    {
        return Database.getQueryLocator(q);
    }
    
    global void execute(Database.BatchableContext BC, List<Sobject> scope)
    {
        delete scope;
    }
    
    global void finish(Database.BatchableContext BC)
    {
        if (qs != null && qs.size() > 0)
        {
            Utility_Batch_Delete proc = new Utility_Batch_Delete(qs, fq);
            Database.executeBatch(proc);
        }
        else
        {
            if (fq != null)
            {
                List<SObject> lst = Database.query(fq);
                delete lst;
            }
        }
    }
}