How to view the complete aggregation statement when using spring data mongodb?

Sage_Justus · 2024-05-17T05:00:55.776Z

I just started using spring data mongodb aggregation query.

fun findRoot(): MarkdownMongoDocument? {
    val aggregation = Aggregation.newAggregation(
        MarkdownMongoDocument::class.java,
        MarkdownMongoRepositoryProperties.findRoot()
    )
    val results = mongoTemplate.aggregate(aggregation, MarkdownMongoDocument::class.java) 
    return results.mappedResults[0]
}

MarkdownMongoRepositoryProperties.findRoot()

public static List<AggregationOperation> findRoot() {
        List<String> jsons = List.of(
                "{ $match: { pid: 0 } }",
                "{$graphLookup:{from:\"t_markdown\",startWith:\"$_id\",connectFromField:\"_id\",connectToField:\"pid\",depthField:\"level\",as:\"children\"}}",
                "{$unwind:{path:\"$children\",preserveNullAndEmptyArrays:true}}",
                "{ $sort: { \"children.level\": -1 } }",
                "{$group:{_id:\"$_id\",title:{$first:\"$title\"},path:{$first:\"$path\"},pid:{$first:\"$pid\"},createUserId:{$first:\"$createUserId\"},isDirectory:{$first:\"$isDirectory\"},children:{$push:\"$children\"}}}",
                "{$addFields:{children:{$reduce:{input:\"$children\",initialValue:{level:-1,presentChild:[],prevChild:[]},in:{$let:{vars:{prev:{$cond:[{$eq:[\"$$value.level\",\"$$this.level\"]},\"$$value.prevChild\",\"$$value.presentChild\"]},current:{$cond:[{$eq:[\"$$value.level\",\"$$this.level\"]},\"$$value.presentChild\",[]]}},in:{level:\"$$this.level\",prevChild:\"$$prev\",presentChild:{$concatArrays:[\"$$current\",[{$mergeObjects:[\"$$this\",{children:{$filter:{input:\"$$prev\",as:\"e\",cond:{$eq:[\"$$e.pid\",\"$$this._id\"]}}}}]}]]}}}}}}}}",
                "{$addFields:{children:\"$children.presentChild\"}}"
                );
       return jsons.stream().map(Aggregation::stage).toList();
    }

As shown above, I did not find a way to directly convert the entire statement into List<AggregationOperation>, I can only split the entire statement.

Then I want to view the query statement processed by spring data mongodb, but the output log is omitted.

2024-05-16T15:45:07.693+08:00 DEBUG 10204 --- [nio-8080-exec-6] org.mongodb.driver.protocol.command      : Command "aggregate" started on database "sage-dev" using a connection with driver-generated ID 3 and server-generated ID 71 to localhost:27017. The request ID is 12 and the operation ID is 11. Command: {"aggregate": "t_markdown", "pipeline": [{"$match": {"pid": 0}}, {"$graphLookup": {"from": "t_markdown", "startWith": "$_id", "connectFromField": "_id", "connectToField": "pid", "depthField": "level", "as": "children"}}, {"$unwind": {"path": "$children", "preserveNullAndEmptyArrays": true}}, {"$sort": {"children.level": -1}}, {"$group": {"_id": "$_id", "title": {"$first": "$title"}, "path": {"$first": "$path"}, "pid": {"$first": "$pid"}, "createUserId": {"$first": "$createUserId"}, "isDirectory": {"$first": "$isDirectory"}, "children": {"$push": "$children"}}}, {"$addFields": {"children": {"$reduce": {"input": "$children", "initialValue": {"level": -1, "presentChild": [], "prevChild": []}, "in": {"$let": {"vars": {"prev": {"$cond": [{"$eq": ["$$value.level", "$$this.level"]}, "$$value.prevChild", "$$value.presentChild"]}, "current": {"$cond": [{"$eq": ["$$value.level", "$$this.level"]}, "$$value.presentChild", []]}}, "in": {"level": "$$this.level", "prevChild": "$$prev", "presentChild" ...

I looked at the code of MongoTemplate and found the following line of key code, but the method is private and I cannot call it.

Document command = aggregationUtil.createCommand(collectionName, aggregation, context);

if (LOGGER.isDebugEnabled()) {
    LOGGER.debug(String.format("Executing aggregation: %s", serializeToJsonSafely(command)));
}

I don’t want to set up spring’s logs anymore.
Is there a way for me to use the entire native statement directly?
How to view the converted statement of spring data mongodb?

Just help me solve one of the 2nd and 3rd questions, thanks.

Aasawari · 2024-05-17T15:27:14.571Z

Hi @Sage_Justus and welcome to the MongoDB community forum.

Can you help me understand if you are trying to write the above aggregation query correctly ?

If yes, you can read the article on MongoDB Advanced Aggregations With Spring Boot and Amazon Corretto to understand how to write complex aggregation queries in MongoDB.

If this does not satisfy your requirements, could you send me more details on the above questions which could help us understand better.

Regards
Aasawari

Sage_Justus · 2024-05-20T06:38:28.200Z

You can check MarkdownMongoRepositoryProperties.findRoot(), now I need to use a list and split a complete string aggregation query statement.
I don’t want to split this string aggregation query statement, how to achieve it?

or How do I view the converted mongodb native aggregate query statement of spring data mongodb?