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Performing update using #Query via Spring Data MongoDB

i wanted to do a direct update to mongodb and setting someflag to either true or false for my use case. To be effecient i do not want to query all documents and set the someflag and save it back to db. i just want to directly update it on db just like when doing update on mongodb terminal.
Here is the sample document. NOTE: these documents can number from 1 ~ N so i need to handle efficiently big datas
{
_id: 60db378d0abb980372f06fc1
someid: 23cad24fc5d0290f7d5274f5
somedata: some data of mine
flag: false
}
Currently im doing an #Query method on my repository
#Query(value ="{someid: ?0}, {$set: {flag: false}}")
void updateFlag(String someid)
Using the above syntax, it doesnt work, i always get an exception message below;
Failed to instantiate void using constructor NO_CONSTRUCTOR with
arguments
How do i perform a direct update effeciently without querying all those document and updating it back to db?

Use the BulkOperations class (https://docs.spring.io/spring-data/mongodb/docs/current/api/org/springframework/data/mongodb/core/BulkOperations.html)
Sample codes:
Spring Data Mongodb Bulk Operation Example

Spring R2DBC + SQL Server: procedures query

I am required to execute a stored procedure in a SQL server to fetch some data, and since I will later save the data into a Mongo and this one is with ReactiveMongoTemplate and so on, I introduced Spring R2DBC.
implementation("org.springframework.data:spring-data-r2dbc:1.0.0.RELEASE")
implementation("io.r2dbc:r2dbc-mssql:0.8.1.RELEASE")
I see that I can do SELECT and INSERT and so on with R2DBC, but is it possible to EXEC prod_name? I tried it and it hangs forever and then the test terminates, without success but neither failure. The last line of log is:
io.r2dbc.mssql.QUERY - Executing query: EXEC "SCHEMA"."MY_PROCEDURE"
The code is like:
public Flux<Coupon> selectWithProcedure() {
return databaseClient
.execute("EXEC \"SCHEMA\".\"MY_PROCEDURE\" ")
.as(Coupon.class)
.fetch().all()
.doOnNext(coupon -> {
coupon.setCouponStatusRefFromId(coupon.getCouponStatusRefId());
});
}
And it seems that no data is retrieved.
If I test some other methods with simple queries like SELECT... it works. But the problem is, DBAs do not allow my app to read table data, instead, they create a procedure for me. If this query is not possible, I must go with traditional JPA way and going reactive at Mongo side has lost its sense.

Well. I just saw this:
https://github.com/r2dbc/r2dbc-mssql, version 0.8.1:
Next steps:
Execution of stored procedures
Add support for TVP and UDTs
And:
https://r2dbc.io/2019/05/13/r2dbc-0-8-milestone-8-released
We already have a few tickets lined up for the next milestone, and we know that they will require further SPI modifications:
Support for Auto-Commit
Connection Validation
Support for Stored Procedures

How to use mongoDB $sum in #Query

I'm new user of mongoDB, I have create an application with spring boot/mySql and I want replace database sql to mongoDB.
I did change all things necessary for example, annotations, relations etc ... but I have a problem with request I don't know the similar syntax of #Query in mongoDb.
this my request with sql:
// this calculate the sum of all distance in walk's document
#Query("select sum(distance) from Walk")
public Double sumDistance();
I did read mongoDB aggregate and I know how to use it in console windows with command
$ mongo
$ db.walk.aggregate([{$group:{"_id":"$dateWalk",Count:{$sum:"$distance"}}}])
but, I want use $sum in my program java not in console.
So please, I need your help about the syntax similar to this with mongoDB
// this calculate the sum of all distance in walk's document
#Query("select sum(distance) from Walk")
public Double sumDistance();
thanks in advance :)

You would need to create a custom Repository that would implement the aggregation.
Examples:
https://www.javacodegeeks.com/2016/04/data-aggregation-spring-data-mongodb-spring-boot.html
https://github.com/spring-projects/spring-data-examples/blob/master/mongodb/aggregation/src/main/java/example/springdata/mongodb/aggregation/OrderRepositoryImpl.java

Converting sql/oracle to java mongodb query

I am new in Mongodb. can anybody tell me any online tool where i can easily convert my sql/ oracle query in mongodb for my java code.
ex:
Simple oracle query:
select * form student where class = "XII" and name="John";
MongoDb Query for java:
db.getCollection("Student", Student.class).find(and(eq("class" , "XII"), eq("name", "John"))).into(new ArrayList<Employee>());
so i want a query builder for java where i can pass the sql/oracle query and i will get Java code for mongodb as Output.
Please suggest some useful .

I don't think if there is any converter available but I will suggest you to learn it by this best free quick course
https://university.mongodb.com/courses/MongoDB/M101J/

using $addToset with java morphia aggregation

I have mongodb aggregation query and it works perfectly in shell.
How can i rewrite this query to use with morphia ?
org.mongodb.morphia.aggregation.Group.addToSet(String field) accepts only one field name but i need to add object to the set.
Query:
......aggregate([
{$group:
{"_id":"$subjectHash",
"authors":{$addToSet:"$fromAddress.address"},
---->> "messageDataSet":{$addToSet:{"sentDate":"$sentDate","messageId":"$_id"}},
"messageCount":{$sum:1}}},
{$sort:{....}},
{$limit:10},
{$skip:0}
])
Java code:
AggregationPipeline aggregationPipeline = myDatastore.createAggregation(Message.class)
.group("subjectHash",
grouping("authors", addToSet("fromAddress.address")),
--------??????------>> grouping("messageDataSet", ???????),
grouping("messageCount", new Accumulator("$sum", 1))
).sort(...)).limit(...).skip(...);

That's currently not supported but if you'll file an issue I'd be happy to include that in an upcoming release.

Thanks for your answer, I can guess that according to source code. :(
I don't want to use spring-data or java-driver directly (for this project) so I changed my document representation.
Added messageDataSet object which contains sentDate and messageId (and some other nested objects) (these values become duplicated in a document which is a bad design).
Aggregation becomes : "messageDataSet":{$addToSet:"$messageDataSet"},
and Java code is: grouping("messageDataSet", addToSet("messageDataSet")),
This works with moprhia. Thanks.