mongoDB クエリ入門編 #mongoDB

index:

概要:

noSQL型の、mongodb で
クエリのメモとなります。
node.js で monk で接続した場合の例も試してみました。

概要

mongo DB 2.4.14
mongo shell (mongo)
node.js 10.16.0

参考のファイル

github.com

参考

https://qiita.com/nishina555/items/9e20211e8d6f12fdb7b7

https://qiita.com/one-kelvin/items/c0c036f774f0b3b98ae5

mongo shell

・データの登録
Collection 作成、 insert
https://github.com/kuc-arc-f/mongo_1/blob/master/mongo_js/insert_book1.js

use db2;

db.createCollection("books");
db.books.insert({"no" : 1, "title": "t1", "content" : "c1" });
db.books.insert({"no" : 2, "title": "t2", "content" : "c2" });
db.books.insert({"no" : 3, "title": "t3", "content" : "c3" });
db.books.find();

sort

項目を、指定して。sort 実行
　1: 昇順
-1 :　降順

db.books.find().sort({no : -1})

{ "_id" : ObjectId("5d3ba80d60a04da5623c0173"), "no" : 3, "title" : "t3", "content" : "c3" }
{ "_id" : ObjectId("5d3ba80c60a04da5623c0172"), "no" : 2, "title" : "t2", "content" : "c2" }
{ "_id" : ObjectId("5d3ba7ec60a04da5623c0171"), "no" : 1, "title" : "t1", "content" : "c1" }

比較, lt ,gt

・lt
小さい

> db.books.find( {"no": {$lt: 2}} );
{ "_id" : ObjectId("5d3ba7ec60a04da5623c0171"), "no" : 1, "title" : "t1", "content" : "c1" }

・gt
大きい

db.books.find( {"no": {$gt: 2}} );

{ "_id" : ObjectId("5d3ba80d60a04da5623c0173"), "no" : 3, "title" : "t3", "content" : "c3" }

・lte
以下

> db.books.find( {"no": {$lte: 2}} );
{ "_id" : ObjectId("5d3ba7ec60a04da5623c0171"), "no" : 1, "title" : "t1", "content" : "c1" }
{ "_id" : ObjectId("5d3ba80c60a04da5623c0172"), "no" : 2, "title" : "t2", "content" : "c2" }

・gte
　　以上

> db.books.find( {"no": {$gte: 2}} );
{ "_id" : ObjectId("5d3ba80c60a04da5623c0172"), "no" : 2, "title" : "t2", "content" : "c2" }
{ "_id" : ObjectId("5d3ba80d60a04da5623c0173"), "no" : 3, "title" : "t3", "content" : "c3" }

regex , 部分一致検索

データの登録

use db2;

db.createCollection("tasks");
db.tasks.insert({"no" : 1, "title": "t1-title", "content" : "c1-conte" });
db.tasks.insert({"no" : 2, "title": "t2-title", "content" : "c2-conte" });
db.tasks.insert({"no" : 3, "title": "t3-title", "content" : "c3-conte" });
db.tasks.find();

・regex

db.tasks.find({"title": {"$regex": /tit/}}, { title: 1})

> db.tasks.find({"title": {"$regex": /tit/}}, { title: 1});
{ "_id" : ObjectId("5d3bc27ca7ccfe2827b360cf"), "title" : "t1-title" }
{ "_id" : ObjectId("5d3bc27ca7ccfe2827b360d0"), "title" : "t2-title" }
{ "_id" : ObjectId("5d3bc27da7ccfe2827b360d1"), "title" : "t3-title" }

monk / node.js

・sort
https://github.com/kuc-arc-f/mongo_1/blob/master/find_sort.js

var collection = db.get('books');
collection.find({}, {sort: {no: -1}} ,function(e, docs){
    console.log(docs);
    db.close()
});

・比較
https://github.com/kuc-arc-f/mongo_1/blob/master/find_lt.js

var collection = db.get('books');
collection.find( {"no": {$lt: 2}},{},function(e, docs){
    console.log(docs);
    db.close()
});

・regex
https://github.com/kuc-arc-f/mongo_1/blob/master/find_regex.js

var collection = db.get('tasks');
collection.find({"title": {"$regex": /tit/ }}, {} ,function(e, docs){
//    console.log(docs);
    var items = [];
    docs.forEach( function (item) {
        items.push(item);
        console.log(item.title );
    });

    db.close()
});