如何在 MongoDB 中更新多份文件?
您需要使用 multi:true 來更新多份文件。首先,我們用文件來建立集合 -
> db.multiUpdateDemo.insertOne({"ClientName":"John","ClientAge":29}); { "acknowledged" : true, "insertedId" : ObjectId("5cda5bc0b50a6c6dd317adc8") } > db.multiUpdateDemo.insertOne({"ClientName":"Carol","ClientAge":31}); { "acknowledged" : true, "insertedId" : ObjectId("5cda5bc1b50a6c6dd317adc9") } > db.multiUpdateDemo.insertOne({"ClientName":"John","ClientAge":39}); { "acknowledged" : true, "insertedId" : ObjectId("5cda5bc3b50a6c6dd317adca") } > db.multiUpdateDemo.insertOne({"ClientName":"John","ClientAge":41}); { "acknowledged" : true, "insertedId" : ObjectId("5cda5bc5b50a6c6dd317adcb") } > db.multiUpdateDemo.insertOne({"ClientName":"David","ClientAge":35}); { "acknowledged" : true, "insertedId" : ObjectId("5cda5bc6b50a6c6dd317adcc") }
以下是對集合中顯示所有文件的查詢,透過 find() 方法來實現 -
> db.multiUpdateDemo.find().pretty();
這將生成以下輸出 -
{ "_id" : ObjectId("5cda5bc0b50a6c6dd317adc8"), "ClientName" : "John", "ClientAge" : 29 } { "_id" : ObjectId("5cda5bc1b50a6c6dd317adc9"), "ClientName" : "Carol", "ClientAge" : 31 } { "_id" : ObjectId("5cda5bc3b50a6c6dd317adca"), "ClientName" : "John", "ClientAge" : 39 } { "_id" : ObjectId("5cda5bc5b50a6c6dd317adcb"), "ClientName" : "John", "ClientAge" : 41 } { "_id" : ObjectId("5cda5bc6b50a6c6dd317adcc"), "ClientName" : "David", "ClientAge" : 35 }
以下是執行多更新的查詢。現在,3 個客戶端的 ClientName “John”將使用以下查詢來更新年齡 -
> db.multiUpdateDemo.update({'ClientName': 'John'}, {$set: {'ClientAge': 34}}, {multi: true}); WriteResult({ "nMatched" : 3, "nUpserted" : 0, "nModified" : 3 })
讓我們再次檢查文件 -
> db.multiUpdateDemo.find().pretty();
這將生成以下輸出 -
{ "_id" : ObjectId("5cda5bc0b50a6c6dd317adc8"), "ClientName" : "John", "ClientAge" : 34 } { "_id" : ObjectId("5cda5bc1b50a6c6dd317adc9"), "ClientName" : "Carol", "ClientAge" : 31 } { "_id" : ObjectId("5cda5bc3b50a6c6dd317adca"), "ClientName" : "John", "ClientAge" : 34 } { "_id" : ObjectId("5cda5bc5b50a6c6dd317adcb"), "ClientName" : "John", "ClientAge" : 34 } { "_id" : ObjectId("5cda5bc6b50a6c6dd317adcc"), "ClientName" : "David", "ClientAge" : 35 }
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