我们可以在Java中使用_id更新mongodb中的文档吗？

Question

I am trying update document with object id but not getting result. Here is my code please help me

DBCollection patients= db.getCollection("Patients");
    BasicDBObject doc = new BasicDBObject();
            doc.put("name","seshu");


DBObject update=`new` BasicDBObject().append("_id",ObjectId("534e1c8e40a8af540cd01ff4"));

    patients`enter code here`.update(update, doc);

Answer 1

When you say "not getting result", I assume you mean that the document is not being updated?

Are you sure that you have the collection name, database name, and ObjectId correct? And that a document exists in that collection with that ObjectId. You should double check all of this via your program or the mongo shell.

Why don't you also try adding some extra checks/debugging in your code, something like this:

DBCollection patients = db.getCollection("Patients");
DBObject update = new BasicDBObject().append("_id", new ObjectId("..."));

long collectionCount = patients.count();
System.out.println(String.format("Collection count: %s", collectionCount));
long count = patients.count(update);
System.out.println(String.format("Count for query: %s", count));

BasicDBObject doc = new BasicDBObject();
doc.put("name", "seshu");


WriteResult writeResult = patients.update(update, doc);
System.out.println(String.format("Updated %s records", writeResult.getN()));

DBObject updated = patients.findOne(update);
System.out.println(updated);