要删除_id元素,可以使用以下语法-
db.yourCollectionName.find({},{'_id': false}).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.removingidElementDemo.insertOne({"UserName":"John", ... "UserAge":21}); { "acknowledged" : true, "insertedId" : ObjectId("5c9153fd4afe5c1d2279d6ad") } > db.removingidElementDemo.insertOne({"UserName":"Carol", "UserAge":24}); { "acknowledged" : true, "insertedId" : ObjectId("5c9154084afe5c1d2279d6ae") } > db.removingidElementDemo.insertOne({"UserName":"David", "UserAge":22}); { "acknowledged" : true, "insertedId" : ObjectId("5c9154154afe5c1d2279d6af") } > db.removingidElementDemo.insertOne({"UserName":"Mike", "UserAge":26}); { "acknowledged" : true, "insertedId" : ObjectId("5c9154204afe5c1d2279d6b0") } > db.removingidElementDemo.insertOne({"UserName":"Chris", "UserAge":20}); { "acknowledged" : true, "insertedId" : ObjectId("5c91542c4afe5c1d2279d6b1") }
在find()
method的帮助下显示集合中的所有文档。查询如下-
> db.removingidElementDemo.find().pretty();
以下是输出-
{ "_id" : ObjectId("5c9153fd4afe5c1d2279d6ad"), "UserName" : "John", "UserAge" : 21 } { "_id" : ObjectId("5c9154084afe5c1d2279d6ae"), "UserName" : "Carol", "UserAge" : 24 } { "_id" : ObjectId("5c9154154afe5c1d2279d6af"), "UserName" : "David", "UserAge" : 22 } { "_id" : ObjectId("5c9154204afe5c1d2279d6b0"), "UserName" : "Mike", "UserAge" : 26 } { "_id" : ObjectId("5c91542c4afe5c1d2279d6b1"), "UserName" : "Chris", "UserAge" : 20 }
这是从PyMongo中删除_id元素的查询-
> db.removingidElementDemo.find({},{'_id': false}).pretty();
以下是输出,在其中您无法看到_id元素,因为我们已将其删除-
{ "UserName" : "John", "UserAge" : 21 } { "UserName" : "Carol", "UserAge" : 24 } { "UserName" : "David", "UserAge" : 22 } { "UserName" : "Mike", "UserAge" : 26 } { "UserName" : "Chris", "UserAge" : 20 }