英文:
How can I code this Aggregate MongoDB query in Java?
问题
我有这个MongoDB查询：
db.collection.aggregate([{$set: {AllSeasons: {$concatArrays: ["$Seasons",[ "Last season" ],[ "Last season 2" ]]}}},{ $set: { average: { $avg: "$AllSeasons.goals" } } }])
我想在Java中编写这个查询。我尝试了几次，但在$concatArrays处没有获得错误，并且无法解决它。
这是我尝试过的代码：
AggregateIterable<Document> doc = coll.aggregate(Arrays.asList(new Document("$set", new Document("AllSeasons", new Document("$concatArrays", Arrays.asList("$Seasons", Arrays.asList("Last season"), Arrays.asList("Last season 2"))))),new Document("$set", new Document("Average", new Document("$avg", "$AllSeasons.goals")))));
那么，我该如何在Java中编写这个查询呢？
非常感谢！
英文:
I have this MongoDB query:
db.collection.aggregate([{$set: {AllSeasons: {$concatArrays: ["$Seasons",[ "$Last season" ],[ "$Last season 2" ]]}}},{ $set: { average: { $avg: "$AllSeasons.goals" } } }])
I want to code this query in Java. I have made several attempts but I don't get an error with $concatArrays and can't resolve it.
This is what I tried:
AggregateIterable<Document> doc = coll.aggregate(Arrays.asList(new Document("$set", new Document("AllSeasons", new Document("$concatArrays", "[$Seasons, ['$Last season'] , ['$Last season 2']] "))),new Document("$set", new Document("Average", new Document("$avg", "$AllSeasons.goals")))));
So how do I code this query in Java?
Thank you so much!
答案1
得分: 2
希望Mongo查询正常工作。您可以使用mongoTemplate进行操作。
public List<Object> test(){Aggregation aggregation = Aggregation.newAggregation(a -> new Document("$set",new Document("AllSeasons",new Document("$concatArrays",Arrays.asList("$Seasons", Arrays.asList("$Last_season_1"), Arrays.asList("$Last_season_2"))))),b -> new Document("$set",new Document("average",new Document("$avg","$AllSeasons.goals")))).withOptions(AggregationOptions.builder().allowDiskUse(Boolean.TRUE).build());return mongoTemplate.aggregate(aggregation, mongoTemplate.getCollectionName(YOUR_COLLECTION.class), Object.class).getMappedResults();}
英文:
Hope the mongo query is working. And you can go with mongoTemplate
public List<Object> test(){Aggregation aggregation = Aggregation.newAggregation(a-> new Document("$set",new Document("AllSeasons",new Document("$concatArrays",Arrays.asList("$Seasons",Arrays.asList("$Last_season_1"),Arrays.asList("$Last_season_2"))))),b-> new Document("$set",new Document("average",new Document("$avg","$AllSeasons.goals")))).withOptions(AggregationOptions.builder().allowDiskUse(Boolean.TRUE).build());return mongoTemplate.aggregate(aggregation, mongoTemplate.getCollectionName(YOUR_COLLECTION.class), Object.class).getMappedResults();}
通过集体智慧和协作来改善编程学习和解决问题的方式。致力于成为全球开发者共同参与的知识库，让每个人都能够通过互相帮助和分享经验来进步。
评论