MongoDB からのデータの読み取り

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import com.mongodb.ConnectionString
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import com.mongodb.MongoClientSettings
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import com.mongodb.client.model.*
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import com.mongodb.kotlin.client.*
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import org.bson.Document
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fun main() {
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    val uri = "<connection string URI>"
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    val settings = MongoClientSettings.builder()
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        .applyConnectionString(ConnectionString(uri))
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        .retryWrites(true)
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        .build()
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    // Create a new client and connect to the server
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    val mongoClient = MongoClient.create(settings)
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    val database = mongoClient.getDatabase("<database name>")
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    val collection = database.getCollection<Document>("<collection name>")
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    // Start example code here
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    // End example code here
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}

val filter = <filter>
val results = collection.find(filter)
results.forEach { result ->
    print(result)
}

val count = collection.countDocuments()
print(count)

val filter = <filter>
val queryCount = collection.countDocuments(filter)
print(queryCount)

val estimatedCount = collection.estimatedDocumentCount()
print(estimatedCount)

val distinctResults = collection.distinct("<field name>")
distinctResults.forEach { result ->
    print(result)
}

val changeStream = collection.watch()
changeStream.forEach { changeEvent ->
    print(changeEvent)
}