Category Archives: Stack Overflow

how to update fields of a nested object in mongodb?

Leave a reply

Salam (means Hello) :)

I'm using node-mongodb-native driver and I need to update specific fields of objects stored in an array. this is a sample document in my mongodb collection:

{
    "fields" : [ 
        {
            "en" : "birthDate",
            "status" : "enable",
            "index" : 10
        },{
            "en" : "email",
            "status" : "enable",
            "index" : 4
        },{
            "en" : "inviterCode",
            "status" : "enable",
            "index" : 2
        }
    ]
}

and this is my new data:

var newData = [ 
    {
        "en" : "birthDate",
        "status" : "disable",
    },{
        "en" : "email",
        "status" : "disable",
    }
];

as you can see, if en field matches, status field should be updated. I know that following query works for a single update, but how can I achieve multiple updates with a single query?

collection.update(
    {'fields.en': 'birthDate'}, 
    {$set:{'fields.$.status': 'disable'}}, 
    {w:1, multi: true}, 
    function(error, count){

    }
);

Why serving files with nodejs is faster than apache when I use a single mongodb connection? [closed]

Leave a reply

Salam (means Hello) :)

I'm trying to improve speed of my nodejs website which depends on some mongodb operations and serving some static files. I'm using node-mongodb-native driver. as far as I know:

  1. Nodejs is slow on serving static files, nginx or apache are better options for this task.
  2. Caching a single db object and using it during application run time, is faster than calling MongoClient.connect() for every database operation.

nginx is not currently an option for me. So using a single db connection along side using apache for static files should be fastest combination, but tests on a semi-production environment don't verify this theory:

file server / db connection : speed  

nodejs / multiple : 24895ms
apache / multiple : 10770ms

nodejs / single   :  7068ms
apache / single   : 14995ms

So why when using multiple connections, apache makes my application load faster, and when using a single connection, apache makes my application load slower?

display:table & display:table-cell not working in IE9

Leave a reply

Salam (means Hello) :)

I'm trying to implement a 3 column layout for my web page using display:table & display:table-cell. It works fine in firefox and chrome, and I know that this feature should be supported in IE 9, but all I achieved so far is no more than this screenshot:

enter image description here

how can I get this to work in IE 8+ ?

here is my complete code:

(JS Fiddle available)

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Frameset//EN">
<html>
<head>
    <title>test</title>
    <meta http-equiv="Content-Type" Content="text/html;charset=UTF-8">
    <style type="text/css">
        *{
            margin: 0;
            padding: 0;
        }
        html,body{
            width:100%;
            margin:0;
            padding:0;
        }
        .container{
            display:table;
            width:100%;
            border-collapse:separate;
        }
        .col{
            display:table-cell;
        }
        .side-1{
            width:200px;
            background: #efefef;
        }
        .side-2{
            width:200px;
            background: #f8f8f8;
        }
        .content{

        }
        #header,#footer{
            height:40px;
            background: #e4f3fd;
        }
    </style>
</head>
<body>
<div id="header">header</div>
<div class="container">
    <div class="col side-1">
        sidebar 1
        <br>.<br>.<br>.
    </div>
    <div class="col side-2">
        sidebar 2
        <br>.<br>.<br>.
    </div>
    <div class="col content">
        content
        <br>.<br>.<br>.
    </div>
</div>
<div id="footer">footer</div>
</body>
</html>

display:table & display:table-cell not working in IE9

Leave a reply

Salam (means Hello) :)

I'm trying to implement a 3 column layout for my web page using display:table & display:table-cell. It works fine in firefox and chrome, and I know that this feature should be supported in IE 9, but all I achieved so far is no more than this screenshot:

enter image description here

how can I get this to work in IE 8+ ?

here is my complete code:

(JS Fiddle available)

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Frameset//EN">
<html>
<head>
    <title>test</title>
    <meta http-equiv="Content-Type" Content="text/html;charset=UTF-8">
    <style type="text/css">
        *{
            margin: 0;
            padding: 0;
        }
        html,body{
            width:100%;
            margin:0;
            padding:0;
        }
        .container{
            display:table;
            width:100%;
            border-collapse:separate;
        }
        .col{
            display:table-cell;
        }
        .side-1{
            width:200px;
            background: #efefef;
        }
        .side-2{
            width:200px;
            background: #f8f8f8;
        }
        .content{

        }
        #header,#footer{
            height:40px;
            background: #e4f3fd;
        }
    </style>
</head>
<body>
<div id="header">header</div>
<div class="container">
    <div class="col side-1">
        sidebar 1
        <br>.<br>.<br>.
    </div>
    <div class="col side-2">
        sidebar 2
        <br>.<br>.<br>.
    </div>
    <div class="col content">
        content
        <br>.<br>.<br>.
    </div>
</div>
<div id="footer">footer</div>
</body>
</html>

Answer by Nasser Torabzade for How to assign an id value in mongodb?

Leave a reply

I never used mongoose. but if _id is not included in insert query, mongodb driver will generate _ids for you as an ObjectId object. and if you wish to use your own _ids, it's up to you to decide about its type and length, and also you have to guarantee its uniqueness among the collection because any attempt to insert a document with a duplicated _id will fail.

accepted answer of this question may be useful, if you are looking for a method for creating custom _ids that provides a decent degree of guaranteed uniqueness.

Answer by Nasser Torabzade for How to assign an id value in mongodb?

Leave a reply

I never used mongoose. but if _id is not included in insert query, mongodb driver will generate _ids for you as an ObjectId object. and if you wish to use your own _ids, it's up to you to decide about its type and length, and also you have to guarantee its uniqueness among the collection because any attempt to insert a document with a duplicated _id will fail.

accepted answer of this question may be useful, if you are looking for a method for creating custom _ids that provides a decent degree of guaranteed uniqueness.

Answer by Nasser Torabzade for How to assign an id value in mongodb?

Leave a reply

I never used mongoose. but if _id is not included in insert query, mongodb driver will generate _ids for you as an ObjectId object. and if you wish to use your own _ids, it's up to you to decide about its type and length, and also you have to guarantee its uniqueness among the collection because any attempt to insert a document with a duplicated _id will fail.

accepted answer of this question may be useful, if you are looking for a method for creating custom _ids that provides a decent degree of guaranteed uniqueness.