Change Stream Event on an update operation just return the document that changes to, same as oplog. Can I get the document (or some updated values) before update?
MySQL row-based binlog can do this with full binlog_row_image.
No, from change stream an update event looks like:
{
_id: { < Resume Token > },
operationType: 'update',
clusterTime: <Timestamp>,
ns: {
db: 'engineering',
coll: 'users'
},
documentKey: {
_id: ObjectId("58a4eb4a30c75625e00d2820")
},
updateDescription: {
updatedFields: {
email: 'alice@10gen.com'
},
removedFields: ['phoneNumber']
}
}
Only the new values are present, unlike MySQL where you get both after and before.