I'm considering using MongoDb for a backing store for a WPF app that I'm building. Mostly just to get some exposure to NoSQL. Ideally I'd like to make a mongodb database, put it in my application's root folder (or ./data) and connect to it with LINQ -- without having mongo.exe running. I did something similar recently with SQLite and found it to be a great change from XML for data storage.
Is this possible with MongoDb? All the samples that I've seen require mongod.exe to be running when you connect to the database. And the data is always stored in c:\data\db.
Answer, yes. Need to use the --dbpath switch and version 1.5.2 (for "upsert").
Related
I have an existing database for a discord bot in MongoDB Compass v1.28.1 I want to transfer all the data in the database to mongodb atlas because of its more extensive functionality and to not have to wait for compass to take ages to load each time I open it. However when I follow the steps to connect that are provided in Atlas, the pop-up that's supposed to appear when I copy a path to the clipboard doesn't appear, and nothing happens. I tried to connect through my app in VSCode, the same way I did for Compass, using mongoose. Still no collections are loading or any data being stored. I have made my schemas etc. which work perfectly fine in Compass...
Migration to Atlas is documented at https://docs.atlas.mongodb.com/import/
To save you some reads, you have to options - export/import and mongodump/mongorestore.
I would recommend to try export/import first. It's built into Compass https://docs.mongodb.com/compass/current/import-export/ and must be simpler to use considering limited experience with mongo. It's UI oriented so just follow the click-through guide in the documentation.
Unfortunately it has some limitations related to data type conversion from BSON to JSON and may be a bit tedious if you have large number of collections.
In this case you will need to follow CLI mongodump/mongorestore way #barrypicker suggested in the comments. Both commands are available in cmd and PowerShell consoles.
First you backup your local database https://docs.mongodb.com/v4.2/reference/program/mongodump/:
mongodump --uri="mongodb://username:password#localhost:27017/discordbot"
username and password are the ones you use in compass to connect to the source database.
It will create dump directory with all collections you have.
Then you have to upload the backup to Atlas:
mongorestore --uri="mongodb+srv://username:password#cluster.tenant.mongodb.net/database" dump/
username and password are the ones you use to connect to atlas cluster, listed in the "Security/Database Access" section.
You can get the exact subdomains for the --uri part from Atlas. In the dashboard click "Connect" button for the cluster you want to connect to, then choose "shell" as the connection method in the connection pop-up:
We are creating Meteor-based Mongo database manager and we need the ability to "unmount" (remove from system) all collections when we switch databases.
Example:
I'm managing database called dbA. We have all collections for that database created using Mongo.Collection() on server and on client side.
I want to switch database to dbB. I need to unmount all Collections of dbA and mount those of dbB. Reason: dbB could have a collection of the same name as dbA (and usually does)
Is there a way to do this?
Thanks!
You may be able to accomplish this by publishing the necessary data from the new database.
Here's a discussion from a similar question on the Meteor Forums (note the proposed solution at the end):
https://forums.meteor.com/t/switch-database-while-meteor-is-running/4361/5
hi i think you can do with
db.copyDatabase()
run the shell command in the backend from meteor server and execute the copy database command. and after the database is copied you can remove the previous collection.
more detail about copyDatabase() is here
https://docs.mongodb.org/manual/reference/method/db.copyDatabase/
I'm studying meteor and trying some examples on nitrous.io, but the available disk space was soon consumed by the big mongo data files (including the prealloc journal files).
Unfortunately MongoDB is also new to me. I googled around and found that I can start mongoDB with some parameters like --nojournal, but I have no idea where in the nitrous.io app I can pass this parameter to mongodb at startup?
I also can't find any mongodb.conf (even *db.conf) to use the storage.smallFiles setting.
Any help would be appreciated!
Instead of using Meteor's builtin MongoDB instance, you can specify a custom instance (which you can configure the way you want).
To do this Nitrous.IO, you can follow these steps:
Create a box with Meteor template.
Install MongoDB, by running parts install mongodb (Autoparts is Nitrous.IO specific package manager)
Open the MongoDB config located at /home/action/.parts/etc/mongodb.conf
Tweak it to your liking.
Start MongoDB instance by running parts start mongodb
Now you can create a new meteor project - meteor create projectname
Finally, when you're starting meteor on your project specify the MONGO_URL environment variable. eg: MONGO_URL=mongodb://0.0.0.0:27017 meteor.
Hope this would be good enough to get started. You can also upgrade your Nitrous.IO account to increase the storage of your box.
UPDATE: I just noticed that Meteor runs its MongoDB instance with --smallfiles flag set.
I'm having trouble figuring out the answer to this one:
Am I supposed to run one instance of MongoDB for each directory location?
Or am I supposed to store all databases in the same location?
Or Do I run one MongoDB instance and can specify a different location for each database at run time?
You can use the --directoryperdb option of mongodb to store each DB in a different physical location.
I have inserted and fetched data using MongoDB, in PHP. Is there an actual copy of this data in a document somewhere?
By default Mongo stores its data in the directory /data/db.
You can specify a different directory using the --dbpath option.
If you’re running Mongo on Windows then the directory will be C:\data\db, where C is the drive letter of the working directory in which Mongo was started. This is quite confusing, so on Windows I’d recommend that you always specify a data directory using --dbpath.
MongoDB stores it's data in the data directory specified by --dbpath. It uses a database format so it's not actual documents, but there are multiple documents in each file and you cannot easily extract the data from this format yourself.
To read and/or update a document you need to use a MongoDB client, in the same way that you send SQL queries to MySQL through a MySQL client. You probably want to do it programmatically by using one of the client libraries for your programming language, but there is also a command-line client if you need to do manual updates.