def METHOD_NAME(account_name: Optional[str] = None,
                                            database_name: Optional[str] = None,
                                            resource_group_name: Optional[str] = None,
                                            opts: Optional[pulumi.InvokeOptions] = None) -> AwaitableGetMongoDBResourceMongoDBDatabaseResult:
    """
    Gets the MongoDB databases under an existing Azure Cosmos DB database account with the provided name.
    Azure REST API version: 2023-04-15.
    :param str account_name: Cosmos DB database account name.
    :param str database_name: Cosmos DB database name.
    :param str resource_group_name: The name of the resource group. The name is case insensitive.
    """
    __args__ = dict()
    __args__['accountName'] = account_name
    __args__['databaseName'] = database_name
    __args__['resourceGroupName'] = resource_group_name
    opts = pulumi.InvokeOptions.merge(_utilities.get_invoke_opts_defaults(), opts)
    __ret__ = pulumi.runtime.invoke('azure-native:documentdb:getMongoDBResourceMongoDBDatabase', __args__, opts=opts, typ=GetMongoDBResourceMongoDBDatabaseResult).value
    return AwaitableGetMongoDBResourceMongoDBDatabaseResult(
        id=pulumi.get(__ret__, 'id'),
        location=pulumi.get(__ret__, 'location'),
        name=pulumi.get(__ret__, 'name'),
        options=pulumi.get(__ret__, 'options'),
        resource=pulumi.get(__ret__, 'resource'),
        tags=pulumi.get(__ret__, 'tags'),
        type=pulumi.get(__ret__, 'type'))