We Keep Coding

How to upgrade this code to latest Mongo Java driver?

I am working on this legacy application (7 years old). I have many methods that do the same thing that I am trying to upgrade to a newer MongoDB Java driver, but it won't compile.
#Override
public void saveOrUpdatePrinter(Document printer) {
printer.put(PRINTER_COLUMNS.updateDate,new Date());
MongoCollection<Document> collection = mongoTemplate.getCollection("PRINTERS");
printer.remove("_id");
Document query = new Document().append(PRINTER_COLUMNS.internal_id, printer.get(PRINTER_COLUMNS.internal_id));
WriteResult result = collection.update(query, printer, true, false);
logger.debug("saveOrUpdatePrinter updeded records: " + result.getN());
}//
The error is:
The method update(Document, Document, boolean, boolean) is undefined
for the type MongoCollection<Document>
Why was this removed?
printer.remove("_id");
Also I would like to know how to do either update or save on the document in one go?
And what will be the proper way to update a single document in the new (MongoDB Java driver 4.7.0)?
Reading this code a little more seems like it was an attempt to do UPSERT operation (update or insert).

I will try to answer your questions.
Q : How to do either Update or Save on the Document in one go?
-> MongoDB's update method updates the values in the existing document whereas the save method replaces the existing document with the document passed. Nothing happens in one go.
update method only updates which are specific fields which are modified by comparing the fields from the modified document with the original document whereas the save method updates/replaces the values of all the fields of an original document by the taking values from the modified document and setting the values into the original document.
Q : What will be the proper way to update a single document in the new (Mongo Java driver 4.7.0)
-> You should be using updateOne(query, updates, options) to update a single document on a MongoCollection object.
From updateOne docs :
The method accepts a filter that matches the document you want to
update and an update statement that instructs the driver how to change
the matching document. The updateOne() method only updates the first
document that matches the filter.
To perform an update with the updateOne() method, you must pass a
query filter and an update document. The query filter specifies the
criteria for which document to perform the update on and the update
document provides instructions on what changes to make to it.
You can optionally pass an instance of UpdateOptions to the
updateOne() method in order to specify the method's behavior. For
example, if you set the upsert field of the UpdateOptions object to
true, the operation inserts a new document from the fields in both the
query and update document if no documents match the query filter.
Q : Is it seems like it was an attempt to do UPSERT operation (Update or Insert) ?
-> Yes, it's an upsert operation.
Q : Why the code is trying to remove _id from document ?
-> The update method will update the document if the document was found by internal_id. If the document was not found and also if there is no _id field in the document, then the mongoshell will consider it as a new document and will invoke insert method internally via the update method to insert the document. For the insertion to happen, that's why it was removed from document.
Just update the code to this.
#Override
public void saveOrUpdatePrinter(Document printer) {
MongoCollection<Document> collection = mongoTemplate.getCollection("PRINTERS");
Document query = new Document().append(PRINTER_COLUMNS.internal_id, printer.get(PRINTER_COLUMNS.internal_id));
UpdateOptions options = new UpdateOptions().upsert(true);
printer.put(PRINTER_COLUMNS.updateDate,new Date());
UpdateResult result = collection.updateOne(query, printer, options);
logger.debug("saveOrUpdatePrinter updated records: " + result.getModifiedCount());
}

You can update a document using the MongoCollection#updateOne() method
An example would be:
collection.updateOne(Filters.eq("_id", new ObjectId("1234")), Updates.set("date", new Date());

How to use DSL.coalesce with lists of fields?

Using Jooq, I am trying to fetch from a table by id first, if no matches found, then fetch by handle again.
And I want all fields of the returned rows, not just one.
Field<?> firstMatch = DSL.select(Tables.MY_TABLE.fields())
.from(Tables.MY_TABLE.fields())
.where(Tables.MY_TABLE.ID.eq(id))
.asfield(); // This is wrong, because it supports only one field, but above we selected Tables.MY_TABLE.fields(), which is plural.
Field<?> secondMatch = DSL.select(Tables.MY_TABLE.fields())
.from(Tables.MY_TABLE.fields())
.where(Tables.MY_TABLE.HANDLE.eq(handle))
.asfield(); // Same as above.
dslContext.select(DSL.coalesce(firstMatch, secondMatch))
.fetchInto(MyClass.class);
Due to the mistake mentioned above in the code, the following error occurs:
Can only use single-column ResultProviderQuery as a field
I am wondering how to make firstMatch and secondMatch two lists of fields, instead of two fields?
I tried
Field<?>[] secondMatch = DSL.select(Tables.MY_TABLE.fields())
.from(Tables.MY_TABLE.fields())
.where(Tables.MY_TABLE.HANDLE.eq(handle))
.fields();
but the following error occurred in the line containing DSL.coalesce
Type interface org.jooq.Field is not supported in dialect DEFAULT
Thanks in advance!

This sounds much more like something you'd do with a simple OR?
dslContext.selectFrom(MY_TABLE)
.where(MY_TABLE.ID.eq(id))
// The ne(id) part might not be required...
.or(MY_TABLE.ID.ne(id).and(MY_TABLE.HANDLE.eq(handle))
.fetchInto(MyClass.class);
If the two result sets should be completely exclusive, then you can do this:
dslContext.selectFrom(MY_TABLE)
.where(MY_TABLE.ID.eq(id))
.or(MY_TABLE.HANDLE.eq(handle).and(notExists(
selectFrom(MY_TABLE).where(MY_TABLE.ID.eq(id))
)))
.fetchInto(MyClass.class);
If on your database product, a query using OR doesn't perform well, you can write an equivalent query with UNION ALL, which might perform better.

DynamoDB: how to query with multiple filter

I have a table and the structure looks like this:
my table structure
Here correlationId is my hashKey.
I can perform simple query using hashKey:
DynamoDBMapper mapper = new DynamoDBMapper(dynamoDB);
Pickup itemRetrieved = mapper.load(Pickup.class, key);
Now I want to query on basis of fields i.e correlationId, partnerId to get transactionId.
How should I do that?

Here is the sample code with multiple filter.
List<Pickup> pickupList = null;
DynamoDBMapper dynamoDBMapper = new DynamoDBMapper(dynamoDBClient);
Pickup pickup = new Pickup();
pickup.setCorrelationId(correlationId);
Map<String, AttributeValue> attributeValues = new HashMap<>();
attributeValues.put(":partnerId", new AttributeValue(partnerId));
DynamoDBQueryExpression<Pickup> queryExpression = new DynamoDBQueryExpression<Pickup>().withHashKeyValues(pickup)
.withFilterExpression("partnerId = :partnerId")
.withExpressionAttributeValues(attributeValues);
pickupList = dynamoDBMapper.query(Pickup.class, queryExpression);
pickupList.stream().forEach(i -> System.out.println(i.toString()));

Your partition key(correlation Id) is one keys on which you want to retrieve transactionid but it's missing partnerid.
Hence do these 3 steps
Step 1 - build a global secondary index on partnerid
Step 2 - filter on partition id
Step 3 - get transaction id

Query Filtering
DynamoDB’s Query function retrieves items using a primary key or an index key from a Local or Global Secondary Index. Each query can use Boolean comparison operators to control which items will be returned.
With today’s release, we are extending this model with support for query filtering on non-key attributes. You can now include a QueryFilter as part of a call to the Query function. The filter is applied after the key-based retrieval and before the results are returned to you. Filtering in this manner can reduce the amount of data returned to your application while also simplifying and streamlining your code.
The QueryFilter that you pass to the Query API must include one or more conditions. Each condition references an attribute name and includes one or more attribute values, along with a comparison operator. In addition to the usual Boolean comparison operators, you can also use CONTAINS, NOT_CONTAINS, and BEGINS_WITH for string matching, BETWEEN for range checking, and IN to check for membership in a set.
In addition to the QueryFilter, you can also supply a ConditionalOperator. This logical operator (either AND or OR) is used to connect each of the elements in the QueryFilter.

Using MongoDB 3.4 to load and save userdata

How can I find a document and retrieve it if found, but insert and retrieve it if not found in one command?
I have an outline for the formats I wish my documents to look like for a user's data. Here is what it looks like
{
"username": "HeyAwesomePeople",
"uuid": "0f91ede5-54ed-495c-aa8c-d87bf405d2bb",
"global": {},
"servers": {}
}
When a user first logs in, I want to store the first two values of data (username and uuid) and create those empty values (global and servers. Both those global and servers will later on have more information filled into them, but for now they can be blank). But I also don't want to override any data if it already exists for the user.
I would normally use the insertOne or updateOne calls to the collection and then use the upsert (new UpdateOptions().upsert(true)) option to insert if it isn't found but in this case I also need to retrieve the user's document aswell.
So in a case in which the user isn't found in the database, I need to insert the outlined data into the database and return the document saved. In a case where the user is found in the database, I need to just return the document from the database.
How would I go about doing this? I am using the latest version of Mongo which has deprecated the old BasicDBObject types, so I can't find many places online that use the new 'Document' type. Also, I am using the Async driver for java and would like to keep the calls to the minimum.

How can I find a document and retrieve it if found, but insert and retrieve it if not found in one command?
You can use findOneAndUpdate() method to find and update/upsert.
The MongoDB Java driver exposes the same method name findOneAndUpdate(). For example:
// Example callback method for Async
SingleResultCallback<Document> printDocument = new SingleResultCallback<Document>() {
#Override
public void onResult(final Document document, final Throwable t) {
System.out.println(document.toJson());
}
};
Document userdata = new Document("username","HeyAwesomePeople")
.append("uuid", "0f91ede5")
.append("global", new Document())
.append("servers", new Document());
collection.findOneAndUpdate(userdata,
new Document("$set", userdata),
new FindOneAndUpdateOptions()
.upsert(true)
.returnDocument(ReturnDocument.AFTER),
printDocument);
The query above will try to find a document matching userdata; if found set it to the same value as userdata. If not found, the upsert boolean flag will insert it into the collection. The returnDocument option is to return the document after the action is performed.
The upsert and returnDocument flags are part of FindOneAndUpdateOptions
See also MongoDB Async Java Driver v3.4 for tutorials/examples. The above snippet was tested with current version of MongoDB v3.4.x.

How do I query OrientDB Vertex graph object by Record ID in Java?

How do I retrieve an OrientDB Document/Object or Graph object using its Record ID? (Language: Java)
I'm referring to http://orientdb.com/docs/2.0/orientdb.wiki/Tutorial-Record-ID.html and Vertex.getId() / Edge.getId() methods.
It is just like an SQL query "SELECT * from aTable WHERE ID = 1".
Usage/purpose description: I want to store the generated ID after it is created by OrientDB, and later retrieve the same object using the same ID.

(1) I'd suggest using OrientDB 2.1, and its documentation, e.g. http://orientdb.com/docs/2.1/Tutorial-Record-ID.html
(2) From your post, it's unclear to me whether you need help obtaining the RID from the results of a query, or retrieving an object given its RID, so let me begin by mentioning that the former can be accomplished as illustrated by this example (in the case of an INSERT query):
ODocument result=db.command(new OCommandSQL(<INSERTQUERY>)).execute();
System.out.println(result.field("#rid"));
Going the other way around, there are several approaches. I have verified that the following does work using Version 2.1.8:
OrientGraph graph = new OrientGraph("plocal:PATH_TO_DB", "admin", "admin");
Vertex v = graph.getVertex("#16:0");
An alternative and more generic approach is to construct and execute a SELECT query of the form SELECT FROM :RID, along the lines of this example:
List<ODocument> results = db.query(new OSQLSynchQuery<ODocument>("select from " + rid));
for (ODocument aDoc : results) {
System.out.println(aDoc.field("name"));
}
(3) In practice, it will usually be better to use some other "handle" on OrientDB vertices and edges in Java code, or indeed when using any of the supported programming languages. For example, once one has a vertex as a Java Vertex, as in the "Vertex v" example above, one can usually use it.