How to retrieve last update time of each document in MongoDB?

Question

I would like to know if there is a way to get the last update/modify time of data (i.e documents) in a collection in MongoDB. More clearly, I want to make a query to retrieve al

Answer 1

You can either use an audit trail entity as @user1530669 mentioned (I'm calling mine delta - the code is already available somewhere on StackOverflow).

Or you can simply save the last change time. I'm generally using a base entity to set that up and all other entities extend it (for your specific requirement you can probably remove the creationDate as the lastChange is enough for you):

protected Date creationDate;
protected Date lastChange;

// Getters and setters or final setters which don't do anything,
// if you only want to allow the entity to update the values

@PrePersist
public void prePersist() {
    creationDate = (creationDate == null) ? new Date() : creationDate;
    lastChange = (lastChange == null) ? creationDate : new Date();
}

And in your queries you can then add a filter so that the lastChange attribute is more recent than your retrieval limit.