SQLite query result not returned from function - angularjs

Question

What I'm trying to do is create a kind of a storageservice in which I use a SQLite database to store key and value pairs after which I can retrieve them based on the key. To achieve this I set up the following code:
.service('StorageService', function($cordovaSQLite, $q) {
if(window.cordova) {
db = $cordovaSQLite.openDB("vouchers.db");
} else {
db = window.openDatabase("vouchers.db", "1.0", "Vouchers db", -1);
}
$cordovaSQLite.execute(db, "CREATE TABLE IF NOT EXISTS vouchers (key text, value text)");
return {
getItem: function(item) {
var query = "SELECT key, value FROM vouchers WHERE key = ?";
$cordovaSQLite.execute(db,query,[item]).then(function(result) {
console.log(result.rows[0].value);
return result.rows[0].value;
});
},
setItem: function(item, data) {
var query = "INSERT INTO vouchers (key, value) VALUES (?,?)";
return $cordovaSQLite.execute(db, query, [item, data]);
}
};
})
Now, most of this stuff is working great. I can store items in the db and even retrieve and log them from inside the function as you can see on the following line:
console.log(result.rows[0].value);
When I log this I get the expected value, but when I return it and log it in the controller where I'm using this service it's remaining undefined. The code in my controller looks as follows:
var test = StorageService.getItem("testje");
console.log(test);
Please note that there are NO console errors. Just two logs. One from the controller that is undefined, and one from the service that returns the value as intended:
controllers.js:465 undefined
services.js:122 dit is een testje!
I was hoping anyone can tell what is going wrong here. If there's any info or code that can be helpful and I left out, let me know.

Answer 1

That's because your getItem: function(item) { uses a promise to retrieve the results.
Try to change your code to this instead:
getItem: function(item) {
var query = "SELECT key, value FROM vouchers WHERE key = ?";
return $cordovaSQLite.execute(db,query,[item]);
});
and call your service this way:
StorageService.getItem("testje").then(function(result){
console.log(result);
});
You'll be able to view the results then.
I suggest you to study some basic principles of promises: you'll encounter them very often if you use $http get and post requests and any other async stuff in javascript.