使用Java将值添加到MongoDB中的数组 [英] Adding values to an Array in MongoDB with Java

问题描述

我有一个文档存储在mongo数据库的集合中.我希望能够添加到文档中已经存在的两个数组.

I have a document stored in a collection in a mongo database. I want to be able to add to two arrays that are already in the document.

用于创建文档和数组的方法:

Method for creating the document and arrays:

public void addNewListName(String listName) {

    MongoCollection<Document> collection = database.getCollection("lists");

    ArrayList< DBObject > array = new ArrayList< DBObject >();
    Document list = new Document ("name", listName)
            .append("terms", array)
            .append("definitions", array);
    collection.insertOne(list);
}

我要将值添加到数组中的方法:

Method where I want to add values into the array:

public void addVocabToList(String listName, String newVocabTerm, String newDefinition) {

}

图片显示了第一种方法执行后，文档在MongoDB Compass中的外观

The picture shows what the document looks like in MongoDB Compass after the first method is executed

推荐答案

您的 addVocabToList()实现将如下所示:

MongoCollection<Document> collection = database.getCollection("lists");

Document updatedDocument = collection.findOneAndUpdate(
    Filters.eq("name", listName),
    new Document("$push",
        new BasicDBObject("terms", new BsonString(newVocabTerm))
            .append("definitions", new BsonString(newDefinition))),
        new FindOneAndUpdateOptions().returnDocument(ReturnDocument.AFTER));

该代码将:

• 查找具有名称= listName
的文档
• 将 newVocabTerm 的值附加到 terms 数组
• 将 newDefinition 的值附加到 definitions 数组
• 返回更新后的文档(此部分是可选的)

• Find the document having name=listName
• Append the value of newVocabTerm to the terms array
• Append the the value of newDefinition to the definitions array
• Return the updated document (this part is optional)

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