Using database in AngularJS - where should I write DB connection code?

I'm now building up a web app using Node.js, AngularJS and either MySQL or MongoDB. However, when I tried to use AngularJS with a controller which includes datasets fetched from database, I wonder where I should write the code in...

I'm now writing in the following code (search.ejs, not including full portion (such as html tag)):

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.0.8/angular.min.js"></script>
<script src="/javascripts/searchController.js"></script>
<div ng-app class="row" ng-controller="searchCtrl">
<input ng-model="query">
<ul class="search">
<li ng-repeat="i in list" | filter:query">
<a href="{{i.url}}">{{i.name}}</a>
</li>
</ul>
</div>

And I want to fetch data in list from database and use it. So here's searchController.js file:

function searchCtrl($scope){
    $scope.list = [
        {
            'name': 'Michael',
            'url': 'mic'
        },
        {

            'name': 'Bob',
            'url': 'bob'
        }
    ]
}

However, what I want to do is instead of writing out data in the $scope.list variable manually, use data in database of either MySQL or MongoDB. (And MySQL is my preferred language, but MongoDB seems like the better in this case, I think.) So how can I connect to DB?

I also have one file called search.js, which is the following one:

exports.index = function(req, res) {
    res.render("search", {
    }, function(err, res){
        res.render("index", {
            content: res
        });
    });
}

And finally, I also want to hear from you whether I should first save data from database to any file and use it by opening and closing the file, or I should directly connect to database whenever the request comes to fetch data, in terms of performance and security issues, (the data in database would be updated every day, so I have to run a script to automatically recreate the served file anyway).

Thanks.