Java MongoDB:クエリ文書

getdocs

4年前

このチュートリアルでは、コレクションからドキュメントを取得またはクエリする一般的な方法をいくつか紹介します。

テストデータ

テスト用に5つのダミードキュメントを挿入します。

{ "__id" : { "$oid" : "id"} , "number" : 1 , "name" : "mkyong-1"}
{ "__id" : { "$oid" : "id"} , "number" : 2 , "name" : "mkyong-2"}
{ "__id" : { "$oid" : "id"} , "number" : 3 , "name" : "mkyong-3"}
{ "__id" : { "$oid" : "id"} , "number" : 4 , "name" : "mkyong-4"}
{ "__id" : { "$oid" : "id"} , "number" : 5 , "name" : "mkyong-5"}

1. Find（）の例

1.1最初に一致したドキュメントのみを取得する。

    DBObject doc = collection.findOne();
    System.out.println(dbObject);

出力

    { "__id" : { "$oid" : "id"} , "number" : 1 , "name" : "mkyong-1"}

1.2すべての一致文書を取得する。

    DBCursor cursor = collection.find();
    while(cursor.hasNext()) {
        System.out.println(cursor.next());
    }

出力

{ "__id" : { "$oid" : "id"} , "number" : 1 , "name" : "mkyong-1"}
{ "__id" : { "$oid" : "id"} , "number" : 2 , "name" : "mkyong-2"}
{ "__id" : { "$oid" : "id"} , "number" : 3 , "name" : "mkyong-3"}
{ "__id" : { "$oid" : "id"} , "number" : 4 , "name" : "mkyong-4"}
{ "__id" : { "$oid" : "id"} , "number" : 5 , "name" : "mkyong-5"}

1.3一致する文書から単一のフィールドを取得する。

    BasicDBObject allQuery = new BasicDBObject();
    BasicDBObject fields = new BasicDBObject();
    fields.put("name", 1);

    DBCursor cursor = collection.find(allQuery, fields);
    while (cursor.hasNext()) {
        System.out.println(cursor.next());
    }

出力

{ "__id" : { "$oid" : "id"} , "name" : "mkyong-1"}
{ "__id" : { "$oid" : "id"} , "name" : "mkyong-2"}
{ "__id" : { "$oid" : "id"} , "name" : "mkyong-3"}
{ "__id" : { "$oid" : "id"} , "name" : "mkyong-4"}
{ "__id" : { "$oid" : "id"} , "name" : "mkyong-5"}

2. Find（）とComparison

2.1 `number = 5`の文書をすべて取得します。

    BasicDBObject whereQuery = new BasicDBObject();
    whereQuery.put("number", 5);
    DBCursor cursor = collection.find(whereQuery);
    while(cursor.hasNext()) {
        System.out.println(cursor.next());
    }

出力

{ "__id" : { "$oid" : "id"} , "number" : 5 , "name" : "mkyong-5"}

2.2 `$ in`の例 – ` 2、4、5の番号 ‘の文書を取得します。

    BasicDBObject inQuery = new BasicDBObject();
    List<Integer> list = new ArrayList<Integer>();
    list.add(2);
    list.add(4);
    list.add(5);
    inQuery.put("number", new BasicDBObject("$in", list));
    DBCursor cursor = collection.find(inQuery);
    while(cursor.hasNext()) {
        System.out.println(cursor.next());
    }

出力

{ "__id" : { "$oid" : "id"} , "number" : 2 , "name" : "mkyong-2"}
{ "__id" : { "$oid" : "id"} , "number" : 4 , "name" : "mkyong-4"}
{ "__id" : { "$oid" : "id"} , "number" : 5 , "name" : "mkyong-5"}

2.3 `$ gt $ lt`の例 – ` 5> number> 2 `のドキュメントを入手してください。

    BasicDBObject gtQuery = new BasicDBObject();
    gtQuery.put("number", new BasicDBObject("$gt", 2).append("$lt", 5));
    DBCursor cursor = collection.find(gtQuery);
    while(cursor.hasNext()) {
        System.out.println(cursor.next());
    }

出力

{ "__id" : { "$oid" : "id"} , "number" : 3 , "name" : "mkyong-3"}
{ "__id" : { "$oid" : "id"} , "number" : 4 , "name" : "mkyong-4"}

2.4 `$ ne`の例 – ` number！= 4 ‘のドキュメントを取得します。

    BasicDBObject neQuery = new BasicDBObject();
    neQuery.put("number", new BasicDBObject("$ne", 4));
    DBCursor cursor = collection.find(neQuery);
    while(cursor.hasNext()) {
        System.out.println(cursor.next());
    }

出力

{ "__id" : { "$oid" : "id"} , "number" : 1 , "name" : "mkyong-1"}
{ "__id" : { "$oid" : "id"} , "number" : 2 , "name" : "mkyong-2"}
{ "__id" : { "$oid" : "id"} , "number" : 3 , "name" : "mkyong-3"}
{ "__id" : { "$oid" : "id"} , "number" : 5 , "name" : "mkyong-5"}

3. find（）とLogical

3.1 `$と`例 – `number = 2とname = ‘mkyong-2’ ‘のドキュメントを取得します。

    BasicDBObject andQuery = new BasicDBObject();
    List<BasicDBObject> obj = new ArrayList<BasicDBObject>();
    obj.add(new BasicDBObject("number", 2));
    obj.add(new BasicDBObject("name", "mkyong-2"));
    andQuery.put("$and", obj);

    System.out.println(andQuery.toString());

    DBCursor cursor = collection.find(andQuery);
    while (cursor.hasNext()) {
        System.out.println(cursor.next());
    }

出力

{ "$and" :[{ "number" : 2} , { "name" : "mkyong-2"}]}

{ "__id" : { "$oid" : "id"} , "number" : 2 , "name" : "mkyong-2"}

4. find（）とRegex

正規表現パターンで文書を検索する。

4.1 `$ regex`の例 – ` name like pattern ‘Mky。** – [1-3]’、大文字と小文字を区別しない文章を取得する。

    BasicDBObject regexQuery = new BasicDBObject();
    regexQuery.put("name",
        new BasicDBObject("$regex", "Mky.** -[1-3]")
        .append("$options", "i"));

    System.out.println(regexQuery.toString());

    DBCursor cursor = collection.find(regexQuery);
    while (cursor.hasNext()) {
        System.out.println(cursor.next());
    }

出力

{ "name" : { "$regex" : "Mky.** -[1-3]" , "$options" : "i"}}

{ "__id" : { "$oid" : "515ad59e3004c89329c7b259"} , "number" : 1 , "name" : "mkyong-1"}
{ "__id" : { "$oid" : "515ad59e3004c89329c7b25a"} , "number" : 2 , "name" : "mkyong-2"}
{ "__id" : { "$oid" : "515ad59e3004c89329c7b25b"} , "number" : 3 , "name" : "mkyong-3"}

5.完全な例

package com.mkyong.core;

import java.net.UnknownHostException;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.List;

import com.mongodb.BasicDBObject;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBCursor;
import com.mongodb.DBObject;
import com.mongodb.Mongo;
import com.mongodb.MongoException;
/** **
 **  Java MongoDB : Query document
 **
 **  @author mkyong
 **
 ** /public class QueryApp {

    public static void insertDummyDocuments(DBCollection collection) {

        List<DBObject> list = new ArrayList<DBObject>();

        Calendar cal = Calendar.getInstance();

        for (int i = 1; i <= 5; i++) {

            BasicDBObject data = new BasicDBObject();
            data.append("number", i);
            data.append("name", "mkyong-" + i);
           //data.append("date", cal.getTime());

           //+1 day
            cal.add(Calendar.DATE, 1);

            list.add(data);

        }

        collection.insert(list);

    }

    public static void main(String[]args) {

    try {

      Mongo mongo = new Mongo("localhost", 27017);
      DB db = mongo.getDB("yourdb");

     //get a single collection
      DBCollection collection = db.getCollection("dummyColl");

      insertDummyDocuments(collection);

      System.out.println("1. Find first matched document");
      DBObject dbObject = collection.findOne();
      System.out.println(dbObject);

      System.out.println("\n1. Find all matched documents");
      DBCursor cursor = collection.find();
      while (cursor.hasNext()) {
        System.out.println(cursor.next());
      }

      System.out.println("\n1. Get 'name' field only");
      BasicDBObject allQuery = new BasicDBObject();
      BasicDBObject fields = new BasicDBObject();
      fields.put("name", 1);

      DBCursor cursor2 = collection.find(allQuery, fields);
      while (cursor2.hasNext()) {
        System.out.println(cursor2.next());
      }

      System.out.println("\n2. Find where number = 5");
      BasicDBObject whereQuery = new BasicDBObject();
      whereQuery.put("number", 5);
      DBCursor cursor3 = collection.find(whereQuery);
      while (cursor3.hasNext()) {
        System.out.println(cursor3.next());
      }

      System.out.println("\n2. Find where number in 2,4 and 5");
      BasicDBObject inQuery = new BasicDBObject();
      List<Integer> list = new ArrayList<Integer>();
      list.add(2);
      list.add(4);
      list.add(5);
      inQuery.put("number", new BasicDBObject("$in", list));
      DBCursor cursor4 = collection.find(inQuery);
      while (cursor4.hasNext()) {
        System.out.println(cursor4.next());
      }

      System.out.println("\n2. Find where 5 > number > 2");
      BasicDBObject gtQuery = new BasicDBObject();
      gtQuery.put("number", new BasicDBObject("$gt", 2).append("$lt", 5));
      DBCursor cursor5 = collection.find(gtQuery);
      while (cursor5.hasNext()) {
        System.out.println(cursor5.next());
      }

      System.out.println("\n2. Find where number != 4");
      BasicDBObject neQuery = new BasicDBObject();
      neQuery.put("number", new BasicDBObject("$ne", 4));
      DBCursor cursor6 = collection.find(neQuery);
      while (cursor6.hasNext()) {
        System.out.println(cursor6.next());
      }

      System.out.println("\n3. Find when number = 2 and name = 'mkyong-2' example");
      BasicDBObject andQuery = new BasicDBObject();

      List<BasicDBObject> obj = new ArrayList<BasicDBObject>();
      obj.add(new BasicDBObject("number", 2));
      obj.add(new BasicDBObject("name", "mkyong-2"));
      andQuery.put("$and", obj);

      System.out.println(andQuery.toString());

      DBCursor cursor7 = collection.find(andQuery);
      while (cursor7.hasNext()) {
        System.out.println(cursor7.next());
      }

      System.out.println("\n4. Find where name = 'Mky.** -[1-3]', case sensitive example");
      BasicDBObject regexQuery = new BasicDBObject();
      regexQuery.put("name",
        new BasicDBObject("$regex", "Mky.** -[1-3]")
                    .append("$options", "i"));

      System.out.println(regexQuery.toString());

      DBCursor cursor8 = collection.find(regexQuery);
      while (cursor8.hasNext()) {
        System.out.println(cursor8.next());
      }

      collection.drop();

      System.out.println("Done");

     } catch (UnknownHostException e) {
        e.printStackTrace();
     } catch (MongoException e) {
        e.printStackTrace();
     }

    }
}

完了しました。

参考文献

http://docs.mongodb.org/manual/reference/operators/

[クエリ、アップデート、および

投影演算子クイックリファレンス]

mongodb

query