如何在 MongoDB 中进行聚合后更新?
要更新文档,不能使用聚合管道。您可以使用 update()。让我们首先使用文档创建一个集合 -
> db.demo376.insertOne( ... { ... ... "id" :101, ... ... "details" : [ ... { ... Name:"Chris", ... Age:21, ... Score:45 ... }, ... { ... Name:"David", ... Age:23, ... Score:67 ... }, ... { ... Name:"Bob", ... Age:20, ... Score:54 ... } ... ] ... } ... ) { "acknowledged" : true, "insertedId" : ObjectId("5e5a71b92ae06a1609a00b0d") }
使用 find() 方法从集合中显示所有文档 -
> db.demo376.find().pretty();
这将产生以下输出 -
{ "_id" : ObjectId("5e5a71b92ae06a1609a00b0d"), "id" : 101, "details" : [ { "Name" : "Chris", "Age" : 21, "Score" : 45 }, { "Name" : "David", "Age" : 23, "Score" : 67 }, { "Name" : "Bob", "Age" : 20, "Score" : 54 } ] }
以下是更新查询 -
> db.demo376.update( ... {"id" :101}, ... {$inc:{"details.$[d].Age":3}}, ... {arrayFilters: [ {$and:[{"d.Age": 21},{"d.Score": {"$gt":40}} ]}] } ... ) WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
使用 find() 方法从集合中显示所有文档 -
> db.demo376.find().pretty();
这将产生以下输出 -
{ "_id" : ObjectId("5e5a71b92ae06a1609a00b0d"), "id" : 101, "details" : [ { "Name" : "Chris", "Age" : 24, "Score" : 45 }, { "Name" : "David", "Age" : 23, "Score" : 67 }, { "Name" : "Bob", "Age" : 20, "Score" : 54 } ] }
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