获取 MongoDB 集合中的最大元素?
mongodbdatabasebig data analytics更新于 2026/1/6 17:07:17
要获取集合中的最大元素，请按 limit 降序排序。让我们创建一个包含文档的集合 −
>
> db.demo669.insertOne({"Marks":76});
{
"acknowledged" : true,
"insertedId" : ObjectId("5ea3133c04263e90dac943d9")
}
> db.demo669.insertOne({"Marks":55});
{
"acknowledged" : true,
"insertedId" : ObjectId("5ea3133f04263e90dac943da")
}
> db.demo669.insertOne({"Marks":89});
{
"acknowledged" : true,
"insertedId" : ObjectId("5ea3134204263e90dac943db")
}
> db.demo669.insertOne({"Marks":88});
{
"acknowledged" : true,
"insertedId" : ObjectId("5ea3134504263e90dac943dc")
}
> db.demo669.insertOne({"Marks":79});
{
"acknowledged" : true,
"insertedId" : ObjectId("5ea3134e04263e90dac943dd")
}
借助 find() 方法显示集合中的所有文档 −
> db.demo669.find();
这将产生以下输出 −
{ "_id" : ObjectId("5ea3133c04263e90dac943d9"), "Marks" : 76 }
{ "_id" : ObjectId("5ea3133f04263e90dac943da"), "Marks" : 55 }
{ "_id" : ObjectId("5ea3134204263e90dac943db"), "Marks" : 89 }
{ "_id" : ObjectId("5ea3134504263e90dac943dc"), "Marks" : 88 }
{ "_id" : ObjectId("5ea3134e04263e90dac943dd"), "Marks" : 79 }
以下是从集合中获取最大元素的查询 −
> db.demo669.find().sort({"Marks":-1}).limit(1);
这将产生以下输出 −
{ "_id" : ObjectId("5ea3134204263e90dac943db"), "Marks" : 89 }
