Check if mongodb database exists?

Question

Is there a possibility to check if a mongo database allready exists?

Answer 1

Yes, you can get the list of existing databases. From the Java driver you could do something like this to get the database names on a mongod server running on localhost

Mongo mongo = new Mongo( "127.0.0.1", 27017 );
List<String> databaseNames = mongo.getDatabaseNames();

This is equivalent to the mongo shell "show dbs" command. I am sure similar methods exist in all of the drivers.

Answer 2

using MongoDb c# Driver 2.4

    private bool DatabaseExists(string database)
    {
       // _client is IMongoClient
        var dbList = _client.ListDatabases().ToList().Select(db => db.GetValue("name").AsString);
        return dbList.Contains(database);
    }

usage:

        if (!DatabaseExists("FooDb")
        {
            // create and seed db

        }

Answer 3

The PyMongo example above didn't work for me, so I rewrote it using the more standard list_databases() method to the MongoClient library:

from pymongo import MongoClient db_name = "foo" conn = MongoClient('mongodb://localhost,localhost:27017') if bool(db_name in conn.list_databases()): print true # or return true here else: print false # or return false here