MongoDB中的“切换”查询？
您需要找到文档，然后需要使用update来切换查询。首先让我们创建一个包含文档的集合-
> db.toggleDemo.insertOne({"CustomerName":"John Smith","CustomerAge":28,"isMarried":true});
{
"acknowledged" : true,
"insertedId" : ObjectId("5cc7be138f9e6ff3eb0ce43b")
}
> db.toggleDemo.insertOne({"CustomerName":"David Miller","CustomerAge":25,"isMarried":false});
{
"acknowledged" : true,
"insertedId" : ObjectId("5cc7be2e8f9e6ff3eb0ce43c")
}以下是在find()方法的帮助下显示集合中所有文档的查询-
> db.toggleDemo.find().pretty();
这将产生以下输出-
{
"_id" : ObjectId("5cc7be138f9e6ff3eb0ce43b"),
"CustomerName" : "John Smith",
"CustomerAge" : 28,
"isMarried" : true
}
{
"_id" : ObjectId("5cc7be2e8f9e6ff3eb0ce43c"),
"CustomerName" : "David Miller",
"CustomerAge" : 25,
"isMarried" : false
}在MongoDB中切换查询-
> var value = db.toggleDemo.findOne({CustomerName:"David Miller"});
> db.toggleDemo.update({CustomerName:"David Miller"}, {$set: {isMarried: !value.isMarried}});
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })让我们使用isMarried：false检查文档是否已切换为true。现在，我们将显示集合中的所有文档-
> db.toggleDemo.find().pretty();
这将产生以下输出-
{
"_id" : ObjectId("5cc7be138f9e6ff3eb0ce43b"),
"CustomerName" : "John Smith",
"CustomerAge" : 28,
"isMarried" : true
}
{
"_id" : ObjectId("5cc7be2e8f9e6ff3eb0ce43c"),
"CustomerName" : "David Miller",
"CustomerAge" : 25,
"isMarried" : true
}