Sugar ORM - save（）和update（）之间的区别

Question

糖ORM中save（）和update（）有什么区别？

参考此Sugar ORM in Android: update a saved object in SQLite

保存和更新会得到相同的结果吗？

我想更新现有记录，如果存在怎么做？

这里我想做点什么：

 long count = Lead.count(Lead.class);
                            if (count > 0) {
                                List<Lead> leads = Lead.find(Lead.class, "lead_id = ?", leadItem.leadId);

                                if (leads == null) { // save leadItem
                                    Lead.save(lead);
                                    logFile.writeLog("Home Activity: Lead saved in local DB. Lead Id is: " + leadItem.leadId + " leadItem Name: " + leadItem.name);
                                    Log.d("Lead saved: ", leadItem.toString());
                                } else { // update leadItem
                                    Lead.update(lead);
                                    logFile.writeLog("Home Activity: Lead updated in local DB. Lead Id is: " + leadItem.leadId + " leadItem Name: " + leadItem.name);
                                    Log.d("Lead updated: ", leadItem.toString());
                                }
                            }

这里当我调用update时，它还会更新另一条记录，我用不同的ID保存并添加为新记录而不是更新。