我们可以从MongoDB查询结果中删除_id吗？
要从MongoDB结果中删除_id，您需要将_id字段设置为0。以下是语法
db.yourCollectionName.find({},{_id:0});为了理解它，让我们创建一个包含文档的集合。以下是查询
> db.removeIdDemo.insertOne({"UserName":"John","UserAge":23});
{
"acknowledged" : true,
"insertedId" : ObjectId("5c9bb4042d66697741252440")
}
> db.removeIdDemo.insertOne({"UserName":"Mike","UserAge":27});
{
"acknowledged" : true,
"insertedId" : ObjectId("5c9bb40c2d66697741252441")
}
> db.removeIdDemo.insertOne({"UserName":"Sam","UserAge":34});
{
"acknowledged" : true,
"insertedId" : ObjectId("5c9bb4162d66697741252442")
}
> db.removeIdDemo.insertOne({"UserName":"Carol","UserAge":29});
{
"acknowledged" : true,
"insertedId" : ObjectId("5c9bb4222d66697741252443")
}以下是在find()方法的帮助下显示集合中所有文档的查询
> db.removeIdDemo.find().pretty();
这将产生以下输出
{
"_id" : ObjectId("5c9bb4042d66697741252440"),
"UserName" : "John",
"UserAge" : 23
}
{
"_id" : ObjectId("5c9bb40c2d66697741252441"),
"UserName" : "Mike",
"UserAge" : 27
}
{
"_id" : ObjectId("5c9bb4162d66697741252442"),
"UserName" : "Sam",
"UserAge" : 34
}
{
"_id" : ObjectId("5c9bb4222d66697741252443"),
"UserName" : "Carol",
"UserAge" : 29
}以下是从Mongo结果中删除_id的查询
> db.removeIdDemo.find({},{_id:0});这将产生以下输出
{ "UserName" : "John", "UserAge" : 23 }
{ "UserName" : "Mike", "UserAge" : 27 }
{ "UserName" : "Sam", "UserAge" : 34 }
{ "UserName" : "Carol", "UserAge" : 29 }