在MongoDB中查找不符合条件的记录？
要查找不符合条件的记录，请使用$ne。让我们创建一个包含文档的集合-
> db.demo148.insertOne({"Message":"Hello"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e32fb37fdf09dd6d08539c0")
}
> db.demo148.insertOne({"Message":"Good"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e32fb3efdf09dd6d08539c1")
}
> db.demo148.insertOne({"Message":"Bye"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e32fb42fdf09dd6d08539c2")
}在find()方法的帮助下显示集合中的所有文档-
> db.demo148.find();
这将产生以下输出-
{ "_id" : ObjectId("5e32fb37fdf09dd6d08539c0"), "Message" : "Hello" }
{ "_id" : ObjectId("5e32fb3efdf09dd6d08539c1"), "Message" : "Good" }
{ "_id" : ObjectId("5e32fb42fdf09dd6d08539c2"), "Message" : "Bye" }以下是在MongoDB中查找与条件不匹配的记录的查询-
> db.demo148.find({'Message' : {'$ne' : 'Good'}}).toArray(function(err, output)
... {
... console.log(output);
... });这将产生以下输出-
[
{
"_id" : ObjectId("5e32fb37fdf09dd6d08539c0"),
"Message" : "Hello"
},
{
"_id" : ObjectId("5e32fb42fdf09dd6d08539c2"),
"Message" : "Bye"
}
]