如何使用Realm android更新Table中的值？

Question

I have table say Student .I want to updated the values in the table and it does not have any primary key. I am using Realm Database for the same.

Answer 1

Assume You have VisitingCardPOJO you can find element depending on "no" use findFirst() if you want to update only first element or you can use findAll() you get list of record then you update same way below using for loop

public void updateNewCard(Realm realm, VisitingCardPOJO card) {
            VisitingCardPOJO toEdit = realm.where(VisitingCardPOJO.class)
                    .equalTo("no", card.getNo()).findFirst();
            realm.beginTransaction();
            toEdit.setName(card.getName());
            toEdit.setAddress(card.getAddress());
            realm.commitTransaction();
        }

Answer 2

请注意，如果要更新的新数据或输入为空，Realm将删除该对象。为什么会看到他们的数据消失或突然被删除。