MongoDB useul queries

mongo_useful.md

This assumes we have following schema:

1. Schema for Messages:

mongoose.Schema({
    user: String,
    content: String,
    creation_time: Date,
    to: String,
    chat: mongoose.Schema.Types.ObjectId,
    read: Boolean
});

2. Schema for Thread:

 mongoose.Schema({
    users: [String]
})

1. Update all documents (based on some conditions)

app.get('/api/v1.0/unread/:username/:chat', function (req, res) {
    Message.count({chat: req.params.chat, user: { $ne: req.params.username }, read: false}, function(err, messages) {
        if(err)
            res.send(err);

        res.json({ count: messages});
    });
});

2. Get count of matching Results from messages

//Find messages where chatid matches `chatId` and user is not `username`

Message.count({chat: "chatId", user: { $ne: "username" }, read: false}, function(err, messageCount) {
    if(err)
        //print err
    count = messageCount;
});

3. Retrieve all documents based on some condition

Message.find({chat: "chatId"}, functiont(err, messages) {
    if(err)
        //print err
   //documents: messages
});

4. Retrieve one document based on condition

Message.findOne({chat: "chatId"}, functiont(err, message) {
    if(err)
        //print err
   //document: message
});