使用 Java 批量更新 MongoDB 中的文件

Mehvish Ashiq 2023年1月30日 2022年7月12日
  1. 先決條件
  2. 使用 Java 批量更新 MongoDB 中的文件
  3. 使用 updateMany() 通過向現有文件新增新欄位來執行批量更新
  4. 使用 updateMany() 對匹配過濾器的多個文件中的現有欄位執行批量更新
  5. 使用 updateMany() 對匹配過濾器的嵌入文件執行批量更新
  6. 使用 bulkWrite() API 更新與過濾查詢匹配的現有文件
使用 Java 批量更新 MongoDB 中的文件

本教程是關於使用 Java 驅動程式在 MongoDB 中執行文件的批量更新。我們還將學習如何通過新增新欄位、更改現有欄位或陣列的值或刪除文件來進行更新。

先決條件

對於本教程,我們將使用你必須遵循的以下工具。

  1. Java(我們使用的是 Java 18.0.1.1)
  2. MongoDB 伺服器(我們使用的是 MongoDB 5.0.8)
  3. 程式碼編輯器或任何 Java IDE(我們使用的是 Apache NetBeans IDE 13)
  4. 使用 Maven 或 Gradle 的 Mongo Java Driver Dependencies; 我們在 Maven 中使用它

使用 Java 批量更新 MongoDB 中的文件

當我們需要更新資料庫中的多個文件時,批量更新很有用。現在,問題是,我們要如何更新文件?

我們是否想通過新增新欄位、更新現有欄位或陣列的值或刪除文件來進行更新?要了解所有這些場景,讓我們建立一個集合並插入兩個文件。

建立集合:

db.createCollection('supervisor');

插入第一個文件:

db.supervisor.insertOne(
    {
          "firstname": "Mehvish",
          "lastname": "Ashiq",
          "gender": "Female",
          "contact" : {
              "email":"mehvishofficial@gmail.com",
              "phone" : [
                  {
                      "type" : "official",
                      "number" : "123456789"
                  },
                  {
                       "type" : "personal",
                       "number" : "124578369"
                  },
               ]
          },
          "entries" : [
              { "_id" : 1, "itemsperday" : [ 1,3,4,5,6,7 ] },
              { "_id" : 2, "itemperday" : [ 2,3,4,5,2,7 ] },
              { "_id" : 3, "itemperday" : [ 5,0,0,4,0,1 ] }
           ]
    }
);

插入第二個檔案:

db.supervisor.insertOne(
    {
          "firstname": "Tahir",
          "lastname": "Raza",
          "gender": "Male",
          "contact" : {
              "email":"tahirraza@gmail.com",
              "phone" : [
                  {
                      "type" : "official",
                      "number" : "123478789"
                  },
                  {
                       "type" : "personal",
                       "number" : "122378369"
                  },
               ]
          },
          "entries" : [
              { "_id" : 1, "itemsperday" : [ 4,5,6,7,4,6 ] },
              { "_id" : 2, "itemperday" : [ 2,3,2,7,5,2 ] },
              { "_id" : 3, "itemperday" : [ 5,0,0,1,0,0 ] }
           ]
    }
);

填充集合後,你可以使用 db.supervisor.find().pretty(); 檢視插入的文件。我們將從簡單的解決方案開始,然後轉向一些棘手但有趣的解決方案。

使用 updateMany() 通過向現有文件新增新欄位來執行批量更新

示例程式碼:

//write your package where you want to save your source file
package com.voidtesting.javamongobulkupdateexample;

// import necessary libraries
import com.mongodb.BasicDBObject;
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.MongoClient;
import com.mongodb.MongoException;
import com.mongodb.client.MongoClients;
import com.mongodb.client.MongoCollection;
import org.bson.Document;

// Example_1
public class Example_1 {

    // main method
    public static void main(String[] args) {
        // Replace the connection string with your own connection string
        var uri = "mongodb://localhost:27017";

        // try block
        try ( MongoClient mongoClient = MongoClients.create(uri)) {

            // print message if connection is successfully established
            System.out.println("Connected successfully to server.");

            // get the specified database from the MongoDB server
            MongoDatabase database = mongoClient.getDatabase("bulkUpdate");

            // get the specified collection from the selected database
            MongoCollection<Document> collection = database.getCollection("supervisor");

            // update documents by adding a new field and its value
            collection.updateMany(new BasicDBObject(),
                    new BasicDBObject("$set",
                    new BasicDBObject("status", "Good")));

            // print a new line
            System.out.println();

            // iterate over all documents of the selected collection
            // to print in Java IDE
            collection.find().forEach(doc -> {
                System.out.println(doc.toBsonDocument());
                System.out.println();
            });// end forEach

        } // end try block

        // print error if unable to execute a command
        catch (MongoException error) {
            System.err.println("An error occurred while running a command: " + error);
        }// end catch block

    }// end main method
}//end Example_1

輸出:

{
    "_id": {"$oid": "62a866e592fd89ad9c4932ed"},
    "firstname": "Mehvish",
    "lastname": "Ashiq",
    "gender": "Female",
    "contact": {
        "email": "mehvishofficial@gmail.com",
        "phone": [
            { "type": "official", "number": "123456789"},
            {"type": "personal", "number": "124578369"}
         ]
     },
     "entries": [
         {"_id": 1.0, "itemsperday": [1.0, 3.0, 4.0, 5.0, 6.0, 7.0]},
         {"_id": 2.0, "itemperday": [2.0, 3.0, 4.0, 5.0, 2.0, 7.0]},
         {"_id": 3.0, "itemperday": [5.0, 0.0, 0.0, 4.0, 0.0, 1.0]}
     ],
     "status": "Good"
}

{
    "_id": {"$oid": "62a8670192fd89ad9c4932ee"},
    "firstname": "Tahir",
    "lastname": "Raza",
    "gender": "Male",
    "contact": {
        "email": "tahirraza@gmail.com",
        "phone": [
            {"type": "official", "number": "123478789"},
            {"type": "personal", "number": "122378369"}
         ]
     },
     "entries": [
         {"_id": 1.0, "itemsperday": [4.0, 5.0, 6.0, 7.0, 4.0, 6.0]},
         {"_id": 2.0, "itemperday": [2.0, 3.0, 2.0, 7.0, 5.0, 2.0]},
         {"_id": 3.0, "itemperday": [5.0, 0.0, 0.0, 1.0, 0.0, 0.0]}
     ],
     "status": "Good"
}

我們已經為你格式化了輸出(如上所示),但你將在 IDE 上每行看到一個文件。我們也可以使用 db.supervisor.find().pretty(); 在 mongo shell 上檢視更新的文件。

對於此示例程式碼,我們使用 mongo 集合物件的 updateMany() 方法,該方法接受 filter 查詢和 update 語句來更新匹配的文件。在這裡,我們不是過濾文件,而是向所有現有文件新增一個名為 status 的新欄位(參見上面給出的輸出)。

使用 updateMany() 對匹配過濾器的多個文件中的現有欄位執行批量更新

示例程式碼:

//write your package where you want to save your source file
package com.voidtesting.javamongobulkupdateexample;

// import necessary libraries
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.MongoClient;
import com.mongodb.MongoException;
import com.mongodb.client.MongoClients;
import com.mongodb.client.MongoCollection;
import static com.mongodb.client.model.Filters.eq;
import static com.mongodb.client.model.Updates.combine;
import static com.mongodb.client.model.Updates.set;
import org.bson.Document;

// Example_2
public class Example_2 {

    // main method
    public static void main(String[] args) {
        // Replace the connection string with your own connection string
        var uri = "mongodb://localhost:27017";

        // try block
        try ( MongoClient mongoClient = MongoClients.create(uri)) {

            // print message if connection is successfully established
            System.out.println("Connected successfully to server.");

            // get the specified database from the MongoDB server
            MongoDatabase database = mongoClient.getDatabase("bulkUpdate");

            // get the specified collection from the selected database
            MongoCollection<Document> collection = database.getCollection("supervisor");

            // update the filtered documents by updating the existing field
            collection.updateMany(eq("gender", "Female"),combine(set("gender", "F")));
            collection.updateMany(eq("gender", "Male"),combine(set("gender", "M")));

            System.out.println();
            // iterate over all documents of the selected collection
            // to print in Java IDE
            collection.find().forEach(doc -> {
                System.out.println(doc.toBsonDocument());
                System.out.println();
            });// end forEach

        } // end try block

        // print error if unable to execute a command
        catch (MongoException error) {
            System.err.println("An error occurred while running a command: " + error);
        }// end catch block

    }// end main method
}//end Example_2

輸出:

{
    "_id": {"$oid": "62a866e592fd89ad9c4932ed"},
    "firstname": "Mehvish",
    "lastname": "Ashiq",
    "gender": "F",
    "contact": {
        "email": "mehvishofficial@gmail.com",
        "phone": [
            { "type": "official", "number": "123456789"},
            {"type": "personal", "number": "124578369"}
         ]
     },
     "entries": [
         {"_id": 1.0, "itemsperday": [1.0, 3.0, 4.0, 5.0, 6.0, 7.0]},
         {"_id": 2.0, "itemperday": [2.0, 3.0, 4.0, 5.0, 2.0, 7.0]},
         {"_id": 3.0, "itemperday": [5.0, 0.0, 0.0, 4.0, 0.0, 1.0]}
     ],
     "status": "Good"
}

{
    "_id": {"$oid": "62a8670192fd89ad9c4932ee"},
    "firstname": "Tahir",
    "lastname": "Raza",
    "gender": "M",
    "contact": {
        "email": "tahirraza@gmail.com",
        "phone": [
            {"type": "official", "number": "123478789"},
            {"type": "personal", "number": "122378369"}
         ]
     },
     "entries": [
         {"_id": 1.0, "itemsperday": [4.0, 5.0, 6.0, 7.0, 4.0, 6.0]},
         {"_id": 2.0, "itemperday": [2.0, 3.0, 2.0, 7.0, 5.0, 2.0]},
         {"_id": 3.0, "itemperday": [5.0, 0.0, 0.0, 1.0, 0.0, 0.0]}
     ],
     "status": "Good"
}

此程式碼示例與上一個示例類似,但我們正在更新與過濾器匹配的所有文件中特定欄位的值。

我們使用 updateMany()gender 等於 Femalegender 等於 Male 的所有文件執行批量更新。我們將 "gender": "Female""gender": "Male" 分別更改為 "gender":"F""gender":"M"

到目前為止,我們已經瞭解瞭如何使用 updateMany() 方法新增新欄位或更新第一級現有欄位的值。接下來,我們將學習使用 updateMany() 對滿足過濾器查詢的嵌入式文件進行批量更新。

使用 updateMany() 對匹配過濾器的嵌入文件執行批量更新

示例程式碼:

//write your package where you want to save your source file
package com.voidtesting.javamongobulkupdateexample;

// import necessary libraries
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.MongoClient;
import com.mongodb.MongoException;
import com.mongodb.client.MongoClients;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.model.UpdateOptions;
import org.bson.Document;
import org.bson.conversions.Bson;

// Example_3
public class Example_3 {

    // main method
    public static void main(String[] args) {
        // Replace the connection string with your own connection string
        var uri = "mongodb://localhost:27017";

        // try block
        try ( MongoClient mongoClient = MongoClients.create(uri)) {
            // print message if connection is successfully established
            System.out.println("Connected successfully to server.");

            // get the specified database from the MongoDB server
            MongoDatabase database = mongoClient.getDatabase("bulkUpdate");

            // get the specified collection from the selected database
            MongoCollection<Document> collection = database.getCollection("supervisor");
            // filter
            Bson where = new Document().append("contact.phone.type", "official");
            // update
            Bson update = new Document().append("contact.phone.$.type", "assistant");
            // set
            Bson set = new Document().append("$set", update);

            // update collection
            collection.updateMany(where, set, new UpdateOptions());


            // iterate over all documents of the selected collection
            // to print in Java IDE
            collection.find().forEach(doc -> {
                System.out.println(doc.toBsonDocument());
                System.out.println();
            }); // end forEach

        } // end try block

        // print error if unable to execute a command
        catch (MongoException error) {
            System.err.println("An error occurred while running a command: " + error);
        }// end catch block

    }// end main method
}//end Example_3

輸出:

{
    "_id": {"$oid": "62a866e592fd89ad9c4932ed"},
    "firstname": "Mehvish",
    "lastname": "Ashiq",
    "gender": "F",
    "contact": {
        "email": "mehvishofficial@gmail.com",
        "phone": [
            { "type": "assistant", "number": "123456789"},
            {"type": "personal", "number": "124578369"}
         ]
     },
     "entries": [
         {"_id": 1.0, "itemsperday": [1.0, 3.0, 4.0, 5.0, 6.0, 7.0]},
         {"_id": 2.0, "itemperday": [2.0, 3.0, 4.0, 5.0, 2.0, 7.0]},
         {"_id": 3.0, "itemperday": [5.0, 0.0, 0.0, 4.0, 0.0, 1.0]}
     ],
     "status": "Good"
}

{
    "_id": {"$oid": "62a8670192fd89ad9c4932ee"},
    "firstname": "Tahir",
    "lastname": "Raza",
    "gender": "M",
    "contact": {
        "email": "tahirraza@gmail.com",
        "phone": [
            {"type": "assistant", "number": "123478789"},
            {"type": "personal", "number": "122378369"}
         ]
     },
     "entries": [
         {"_id": 1.0, "itemsperday": [4.0, 5.0, 6.0, 7.0, 4.0, 6.0]},
         {"_id": 2.0, "itemperday": [2.0, 3.0, 2.0, 7.0, 5.0, 2.0]},
         {"_id": 3.0, "itemperday": [5.0, 0.0, 0.0, 1.0, 0.0, 0.0]}
     ],
     "status": "Good"
}

在這個 Java 程式中,我們使用 updateMany() 方法對匹配過濾器查詢的嵌入文件執行批量更新。

在這裡,我們將 contact.phone.type 的值從 official 更新為 assistant。要訪問文件陣列,我們使用位置運算子 ($) 來更新滿足過濾器查詢的第一個陣列值。

在使用位置運算子時,我們還可以指定應該更新哪些陣列元素。我們可以指定要更新的第一個、所有或特定的陣列元素。

為了通過位置運算子指定陣列元素,我們使用 dot notation,一種用於導航 BSON 物件的屬性訪問語法。我們通過以下方式使用位置運算子來更新第一個、所有或指定的陣列元素。

  1. 我們使用位置運算子($)來更新滿足過濾查詢的陣列的第一個元素,而陣列欄位必須是過濾查詢的一部分才能使用位置運算子。

  2. 我們使用所有位置運算子($[])來更新陣列的所有專案(元素)。

  3. 過濾位置運算子 ($[<identifier>]) 用於更新與過濾查詢匹配的陣列元素。在這裡,我們必須在更新操作中包含陣列過濾器,以告知哪些陣列元素需要更新。

    請記住,<identifier> 是我們為陣列過濾器指定的名稱。此值必須以小寫字母開頭,並且只能包含字母數字字元。

使用 bulkWrite() API 更新與過濾查詢匹配的現有文件

示例程式碼:

//write your package where you want to save your source file
package com.voidtesting.javamongobulkupdateexample;

// import necessary libraries
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.MongoClient;
import com.mongodb.MongoException;
import com.mongodb.client.MongoClients;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.model.DeleteOneModel;
import com.mongodb.client.model.UpdateManyModel;
import com.mongodb.client.model.WriteModel;
import java.util.ArrayList;
import java.util.List;
import org.bson.Document;

// Example_4
public class Example_4 {

    // main method
    public static void main(String[] args) {
        // Replace the connection string with your own connection string
        var uri = "mongodb://localhost:27017";

        // try block
        try ( MongoClient mongoClient = MongoClients.create(uri)) {
            // print message if connection is successfully established
            System.out.println("Connected successfully to server.");

            // get the specified database from the MongoDB server
            MongoDatabase database = mongoClient.getDatabase("bulkUpdate");

            // get the specified collection from the selected database
            MongoCollection<Document> collection = database.getCollection("supervisor");

            // create object
            List<WriteModel<Document>> writes = new ArrayList<>();

            // delete the document matching the filter
            writes.add(new DeleteOneModel<>(new Document("firstname", "Tahir")));

            // update document matching the filter
            writes.add(new UpdateManyModel<>(
                    new Document("status", "Good"), // filter
                    new Document("$set", new Document("status", "Excellent")) // update
            ));

            // bulk write
            collection.bulkWrite(writes);

            // iterate over all documents of the selected collection
            // to print in Java IDE
            collection.find().forEach(doc -> {
                System.out.println(doc.toBsonDocument());
                System.out.println();
            });// end forEach

        } // end try block
        catch (MongoException me) {
            System.err.println("An error occurred while running a command: " + me);
        }// end catch block
    }// end main method

}// end Example_4

輸出:

{
    "_id": {"$oid": "62a866e592fd89ad9c4932ed"},
    "firstname": "Mehvish",
    "lastname": "Ashiq",
    "gender": "F",
    "contact": {
        "email": "mehvishofficial@gmail.com",
        "phone": [
            {"type": "assistant", "number": "123456789"},
            {"type": "personal", "number": "124578369"}
        ]
     },
     "entries": [
         {"_id": 1.0, "itemsperday": [1.0, 3.0, 4.0, 5.0, 6.0, 7.0]},
         {"_id": 2.0, "itemperday": [2.0, 3.0, 4.0, 5.0, 2.0, 7.0]},
         {"_id": 3.0, "itemperday": [5.0, 0.0, 0.0, 4.0, 0.0, 1.0]}
     ],
     "status": "Excellent"
}

在此示例中,我們使用 bulkWrite()API 一次執行多個操作(刪除和更新)。DeleteOneModel() 用於刪除匹配過濾器的文件,而我們使用 UpdateManyModel() 更新所有匹配過濾器的文件中已存在欄位的值。

Mehvish Ashiq avatar Mehvish Ashiq avatar

Mehvish Ashiq is a former Java Programmer and a Data Science enthusiast who leverages her expertise to help others to learn and grow by creating interesting, useful, and reader-friendly content in Computer Programming, Data Science, and Technology.

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