使用MongoDB-Java驱动程序从数组中删除条目 [英] Remove an entry from array using MongoDB-Java driver
本文介绍了使用MongoDB-Java驱动程序从数组中删除条目的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
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"
}
]
}
]
}
我需要能够删除itemList的一条记录。
我已完成以下操作:
I need to be able to remove one of records of itemList. I have done the following:
public void removeItemByID(String docID, String itemID) throws Exception {
MongoOperations mongoOperations = mongoConfiguration.getMongoTemplate();
Query query = new Query(where("_id").is(docID).and("itemList.itemID").is(itemID));
mongoOperations.remove(query, Item.class);
}
此方法不具备工作。
但是当我使用带有$ pull方法的BasicDBObject时它工作正常!
这些方法之间有什么区别!
This approach doesn't work. However when I have used the BasicDBObject with $pull approach it works fine ! What's the difference among these approaches !
推荐答案
如果你想删除一个数组,我会使用以下内容: / p>
If you want to remove an array generally I use the following:
BasicDBObject match = new BasicDBObject("_id", "1"); // to match your document
BasicDBObject update = new BasicDBObject("itemList", new BasicDBObject("itemID", "1"));
coll.update(match, new BasicDBObject("$pull", update));
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