使用MongoDB更新数组 [英] Update an array using MongoDB

问题描述

我有JSON，如：

{_ id：1，_ class：com.model.Test ，itemList：[
{itemID：1，itemName：Foo，
resources：[{resourceID：1，resourceName： Foo Test1，}，{resourceID：2，resourceName：Foo
Test2，}]}]}

{ "_id" : "1", "_class" : "com.model.Test", "itemList" : [ { "itemID" : "1", "itemName" : "Foo", "resources" : [ { "resourceID" : "1", "resourceName" : "Foo Test1", }, { "resourceID" : "2", "resourceName" : "Foo Test2", } ] } ] }

我需要能够更新资源列表。
我已完成以下操作：

I need to be able to update the list of resources. I have done the following:

    BasicDBObject updateQuery = new BasicDBObject();
    updateQuery.put("id", "1");

    BasicDBObject updateCommand = new BasicDBObject();

    List<Resource> resources = populateResources();//Fetch a new list of Resources
    updateCommand.put("$push", new BasicDBObject("resources", resources));


    MongoOperations mongoOperations = mongoConfiguration.getMongoTemplate();
    DBCollection db = mongoOperations.getCollection("myCollection");
    db.save(updateCommand);

我收到以下错误：

java.lang.IllegalArgumentException：存储在数据库中的字段不能以$'$ b开头（坏键：'$ push'）

java.lang.IllegalArgumentException: fields stored in the db can't start with '$' (Bad Key: '$push')

当我使用时：

db.update( updateQuery, updateCommand, true, true );

我收到以下异常：

java.lang.IllegalArgumentException：无法序列化类
com.model.Test

java.lang.IllegalArgumentException: can't serialize class com.model.Test

我试过了：
db.updateMulti（updateQuery，updateCommand）;
我没有得到任何例外，也没有任何更新发生在文件中。

I've tried : db.updateMulti(updateQuery, updateCommand); I didn't get neither any exceptions nor any updates takes place into the documents.

所以我在这里缺少什么!!

So what am I missing here !!

推荐答案

save（）方法失败，因为它试图将以下文档插入集合中：{$ push：{resources： [资源列表]}}，$ push不是有效的密钥名称。

The save() method is failing because it is attempting to insert the following document into the collection: {"$push":{"resources":[a list of resources]}}, and "$push" is not a valid key name.

从您的问题看来，似乎您正在尝试将另一个资源文档添加到嵌入文档列表中，资源，在嵌入文档中匹配{ itemID：1}，在itemList中。这是正确的吗？

From your question, it appears as though you are attempting to add another resource document to the list of embedded documents, "resources", inside of the embedded document matching {"itemID" : "1"}, inside of "itemList". Is this correct?

处理嵌入式文档的层次很棘手，但可以这样做：

以下是如何插入以下文档使用JS shell进入资源列表：

Dealing with layers of embedded documents is tricky, but it can be done:
Here is how the following document may be inserted into the "resources" list using the JS shell:

> var docToInsert = { "resourceID" : "3", "resourceName" : "Foo Test3"}
> db.myCollection.update({_id:"1", "itemList.itemID":"1"}, {"$push":{"itemList.$.resources":docToInsert}})
> db.myCollection.find().pretty()
{
    "_class" : "com.model.Test",
    "_id" : "1",
    "itemList" : [
        {
            "itemID" : "1",
            "itemName" : "Foo",
            "resources" : [
                {
                    "resourceID" : "1",
                    "resourceName" : "Foo Test1"
                },
                {
                    "resourceID" : "2",
                    "resourceName" : "Foo Test2"
                },
                {
                    "resourceID" : "3",
                    "resourceName" : "Foo Test3"
                }
            ]
        }
    ]
}
> 

使用$位置运算符更新嵌入文档的文档可在更新中找到文件：
http://www.mongodb.org/显示/ DOCS /更新＃更新 - ％24positionaloperator

The documentation on using the "$" positional operator to update embedded documents may be found in the "Updating" documentation: http://www.mongodb.org/display/DOCS/Updating#Updating-The%24positionaloperator

$ push修饰符的文档也在更新页面上：
http://www.mongodb.org/display/DOCS/Updating#正在更新 - ％24push

The documentation on the "$push" modifier is also on the "Updating" page: http://www.mongodb.org/display/DOCS/Updating#Updating-%24push

从发布的代码中，似乎资源是一个列表。您需要使用的方法是$ pushAll，用于向列表中添加多个值：
http://www.mongodb.org/display/DOCS/Updating#Updating-%24pushAll

From the posted code, it appears as though "resources" is a list. It is possible that the method you need to use is $pushAll, used for adding multiple values to a list: http://www.mongodb.org/display/DOCS/Updating#Updating-%24pushAll

使用Java驱动程序，上面的插入可以这样完成：

Using the Java driver, the above insert may be done like so:

Mongo m = new Mongo("localhost", 27017);
DB db = m.getDB("test");
DBCollection myColl = db.getCollection("myCollection");

BasicDBObject docToInsert = new BasicDBObject("resourceID", "3");
docToInsert.put("resourceName", "Foo Test3");

BasicDBObject updateQuery = new BasicDBObject("_id", "1");
updateQuery.put("itemList.itemID", "1");

BasicDBObject updateCommand = new BasicDBObject("$push", new BasicDBObject("itemList.$.resources", docToInsert));

myColl.update(updateQuery, updateCommand);
System.out.println(myColl.findOne().toString());

以上输出如下：

{ "_class" : "com.model.Test" , "_id" : "1" , "itemList" : [ { "itemID" : "1" , "itemName" : "Foo" , "resources" : [ { "resourceID" : "1" , "resourceName" : "Foo Test1"} , { "resourceID" : "2" , "resourceName" : "Foo Test2"} , { "resourceID" : "3" , "resourceName" : "Foo Test3"}]}]}

希望以上将提高您对使用Java驱动程序更新嵌入式文档如何与Mongo一起工作的理解。我注意到这个问题也与Spring有关（mongoOperations是Spring包中的一个类），我很遗憾不熟悉它。如果您仍然遇到更新问题，那么可能需要另一位熟悉Spring的社区成员也可以提供帮助。

Hopefully, the above will improve your understanding of how updating an embedded document works with Mongo using the Java driver. I notice that this question is also related to Spring ("mongoOperations" is a class from the Spring package), which I am unfortunately not familiar with. If you are still having issues with your update, perhaps another member of the Community who is more familiar with Spring will be able to assist.

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