MongoDB(3) クエリ速習

クエリに挑戦！

サンプルデータ

> db.example.remove()
> for(var i =0; i<6; i++) {
... var doc = {name:'user'+i, point: i*1000};
... db.example.save(doc);
... }
>

全件検索

> db.example.find()
{"_id":ObjectId("4f69766ea84ad157af92c6ab"),"name":"user0","point":0}
{"_id":ObjectId("4f69766ea84ad157af92c6ac"),"name":"user1","point":1000}
{"_id":ObjectId("4f69766ea84ad157af92c6ad"),"name":"user2","point":2000}
{"_id":ObjectId("4f69766ea84ad157af92c6ae"),"name":"user3","point":3000}
{"_id":ObjectId("4f69766ea84ad157af92c6af"),"name":"user4","point":4000}
{"_id":ObjectId("4f69766ea84ad157af92c6b0"),"name":"user5","point":5000}

条件検索

> db.example.find({point:2000})
{ "_id" : ObjectId("4f69766ea84ad157af92c6ad"), "name" : "user2", "point" : 2000 }

ソート（昇順）

> db.example.find().sort({point:1})
{ "_id" : ObjectId("4f69766ea84ad157af92c6ab"), "name" : "user0", "point" : 0 }
{ "_id" : ObjectId("4f69766ea84ad157af92c6ac"), "name" : "user1", "point" : 1000 }
{ "_id" : ObjectId("4f69766ea84ad157af92c6ad"), "name" : "user2", "point" : 2000 }
{ "_id" : ObjectId("4f69766ea84ad157af92c6ae"), "name" : "user3", "point" : 3000 }
{ "_id" : ObjectId("4f69766ea84ad157af92c6af"), "name" : "user4", "point" : 4000 }
{ "_id" : ObjectId("4f69766ea84ad157af92c6b0"), "name" : "user5", "point" : 5000 }

ソート（降順）

> db.example.find().sort({point:-1})
{ "_id" : ObjectId("4f69766ea84ad157af92c6b0"), "name" : "user5", "point" : 5000 }
{ "_id" : ObjectId("4f69766ea84ad157af92c6af"), "name" : "user4", "point" : 4000 }
{ "_id" : ObjectId("4f69766ea84ad157af92c6ae"), "name" : "user3", "point" : 3000 }
{ "_id" : ObjectId("4f69766ea84ad157af92c6ad"), "name" : "user2", "point" : 2000 }
{ "_id" : ObjectId("4f69766ea84ad157af92c6ac"), "name" : "user1", "point" : 1000 }
{ "_id" : ObjectId("4f69766ea84ad157af92c6ab"), "name" : "user0", "point" : 0 }

リミット

>db.example.find().limit(2)
{ "_id" : ObjectId("4f69766ea84ad157af92c6ab"), "name" : "user0", "point" : 0 }
{ "_id" : ObjectId("4f69766ea84ad157af92c6ac"), "name" : "user1", "point" : 1000 }

オフセット

> db.example.find().skip(4)
{ "_id" : ObjectId("4f69766ea84ad157af92c6af"), "name" : "user4", "point" : 4000 }
{ "_id" : ObjectId("4f69766ea84ad157af92c6b0"), "name" : "user5", "point" : 5000 }

リミット＆オフセット（ページング）

> db.example.find().skip(2).limit(2)
{ "_id" : ObjectId("4f69766ea84ad157af92c6ad"), "name" : "user2", "point" : 2000 }
{ "_id" : ObjectId("4f69766ea84ad157af92c6ae"), "name" : "user3", "point" : 3000 }

条件演算子（条件演算子一覧はここ）

> db.example.find({point:{$gte:3000}})
{ "_id" : ObjectId("4f69766ea84ad157af92c6ae"), "name" : "user3", "point" : 3000 }
{ "_id" : ObjectId("4f69766ea84ad157af92c6af"), "name" : "user4", "point" : 4000 }
{ "_id" : ObjectId("4f69766ea84ad157af92c6b0"), "name" : "user5", "point" : 5000 }

カーソル

> var cursor = db.example.find();

> cursor.hasNext()
true

> cursor.next()
{
        "_id" : ObjectId("4f69766ea84ad157af92c6ab"),
        "name" : "user0",
        "point" : 0
}

>while (cursor.hasNext()){printjson(cursor.next());}
{
        "_id" : ObjectId("4f69766ea84ad157af92c6ac"),
        "name" : "user1",
        "point" : 1000
}
{
        "_id" : ObjectId("4f69766ea84ad157af92c6ad"),
        "name" : "user2",
        "point" : 2000
}
{
        "_id" : ObjectId("4f69766ea84ad157af92c6ae"),
        "name" : "user3",
        "point" : 3000
}
{
        "_id" : ObjectId("4f69766ea84ad157af92c6af"),
        "name" : "user4",
        "point" : 4000
}
{
        "_id" : ObjectId("4f69766ea84ad157af92c6b0"),
        "name" : "user5",
        "point" : 5000
}

まとめ

MongoDBのクエリー単純で簡単。

かねこ(~_~)