在MongoDB中找到带有ObjectID的文档？
要在MongoDB中查找带有Objectid的文档，请使用以下语法-
db.yourCollectionName.find({"_id":ObjectId("yourObjectIdValue")}).pretty();为了理解上述语法，让我们用文档创建一个集合。使用文档创建集合的查询如下-
> db.findDocumentWithObjectIdDemo.insertOne({"UserName":"Larry"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5c90e4384afe5c1d2279d69b")
}
> db.findDocumentWithObjectIdDemo.insertOne({"UserName":"Mike","UserAge":23});
{
"acknowledged" : true,
"insertedId" : ObjectId("5c90e4444afe5c1d2279d69c")
}
> db.findDocumentWithObjectIdDemo.insertOne({"UserName":"Carol","UserAge":26,"UserHobby":["Learning","Photography"]});
{
"acknowledged" : true,
"insertedId" : ObjectId("5c90e4704afe5c1d2279d69d")
}在find()method的帮助下显示集合中的所有文档。查询如下-
> db.findDocumentWithObjectIdDemo.find().pretty();
以下是输出-
{ "_id" : ObjectId("5c90e4384afe5c1d2279d69b"), "UserName" : "Larry" }
{
"_id" : ObjectId("5c90e4444afe5c1d2279d69c"),
"UserName" : "Mike",
"UserAge" : 23
}
{
"_id" : ObjectId("5c90e4704afe5c1d2279d69d"),
"UserName" : "Carol",
"UserAge" : 26,
"UserHobby" : [
"Learning",
"Photography"
]
}情况1-这是在MongoDB中查找具有ObjectId的文档的查询。
> db.findDocumentWithObjectIdDemo.find({"_id":ObjectId("5c90e4704afe5c1d2279d69d")}).pretty();以下是输出-
{
"_id" : ObjectId("5c90e4704afe5c1d2279d69d"),
"UserName" : "Carol",
"UserAge" : 26,
"UserHobby" : [
"Learning",
"Photography"
]
}情况2-这是在MongoDB中查找具有ObjectId的另一个文档的查询。
查询如下-
> db.findDocumentWithObjectIdDemo.find({"_id": ObjectId("5c90e4444afe5c1d2279d69c")}).pretty();以下是输出-
{
"_id" : ObjectId("5c90e4444afe5c1d2279d69c"),
"UserName" : "Mike",
"UserAge" : 23
}