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I want to be able to execute the following console command to return all rows with only a subset of fields populated but using Spring's MongoTemplate class:
Console Command
db.person.find(null,{name:1}) MongoTemplate
mongoTemplate.find(new Query(...), Person.class) Info on projection (subset) queries can be found in the MongoDB manual.
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To perform and aggregation, first, create aggregation pipelines using the static builder methods on Aggregation class, then create an instance of Aggregation using the newAggregation() method on the Aggregation class and finally run the aggregation using MongoTemplate: MatchOperation matchStage = Aggregation.
@Document is an annotation provided by Spring data project. It is used to identify a domain object, which is persisted to MongoDB. So you can use it to map a Java class into a collection inside MongoDB. If you don't use Spring Data, you don't need this annotation.
MongoRepository is an interface provided by Spring Data in the package org. springframework. data. mongodb.
The @Id annotation tells the mapper which property you want to use for the MongoDB _id property and the @Indexed annotation tells the mapping framework to call ensureIndex on that property of your document, making searches faster.
Query q = new Query(); q.fields().include("name"); mongoTemplate.find(q, Person.class); mongoTemplate.getCollection(COLLECTION).find(null, new BasicDBObject(FIELD, "1")) If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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