根据 MongoDB 中匹配的字段进行条件更新
mongodbdatabasebig data analytics更新于 2026/1/10 4:07:17
对于条件更新，请使用 update() 并使用 $set 设置新值。让我们创建一个包含文档的集合 −
> db.demo150.insertOne({"StudentId":101,"StudentName":"Chris","StudentMarks":35});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e350dcdfdf09dd6d08539d3")
}
> db.demo150.insertOne({"StudentId":102,"StudentName":"Chris","StudentMarks":55});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e350dcefdf09dd6d08539d4")
}
> db.demo150.insertOne({"StudentId":103,"StudentName":"David","StudentMarks":34});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e350dcffdf09dd6d08539d5")
}
> db.demo150.insertOne({"StudentId":104,"StudentName":"Chris","StudentMarks":38});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e350dd0fdf09dd6d08539d6")
}
使用 find() 方法显示集合中的所有文档 −
> db.demo150.find();
将产生以下输出 −
{ "_id" : ObjectId("5e350dcdfdf09dd6d08539d3"), "StudentId" : 101, "StudentName" : "Chris", "StudentMarks" : 35 }
{ "_id" : ObjectId("5e350dcefdf09dd6d08539d4"), "StudentId" : 102, "StudentName" : "Chris", "StudentMarks" : 55 }
{ "_id" : ObjectId("5e350dcffdf09dd6d08539d5"), "StudentId" : 103, "StudentName" : "David", "StudentMarks" : 34 }
{ "_id" : ObjectId("5e350dd0fdf09dd6d08539d6"), "StudentId" : 104, "StudentName" : "Chris", "StudentMarks" : 38 }
以下是根据匹配字段进行条件更新的查询 −
> db.demo150.update({"StudentId":103},{$set:{"StudentMarks":97}});
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
使用 find() 方法显示集合中的所有文档 −
> db.demo150.find();
这将产生以下输出 −
{ "_id" : ObjectId("5e350dcdfdf09dd6d08539d3"), "StudentId" : 101, "StudentName" : "Chris", "StudentMarks" : 35 }
{ "_id" : ObjectId("5e350dcefdf09dd6d08539d4"), "StudentId" : 102, "StudentName" : "Chris", "StudentMarks" : 55 }
{ "_id" : ObjectId("5e350dcffdf09dd6d08539d5"), "StudentId" : 103, "StudentName" : "David", "StudentMarks" : 97 }
{ "_id" : ObjectId("5e350dd0fdf09dd6d08539d6"), "StudentId" : 104, "StudentName" : "Chris", "StudentMarks" : 38 }
