Retrieve res var from $cordovaSQLite in cordova/phonegap

I'm trying to get data from a database but I don't know how to stock the result in a variable even if the variable is global. Here is my code:

.factory('Requirements', function($cordovaSQLite) {
  return {
    get: function() {
      //Vérification de l'existance
      var result = false;
      query = "select id, instagram_client_id, instagram_client_secret, twitter_client_id, twitter_client_secret from requirements WHERE id = 1";
      $cordovaSQLite.execute(db, query, []).then(function(res) {
          if(res.rows.length == 0) {
              query = "INSERT INTO requirements(id, instagram_client_id, instagram_client_secret, twitter_client_id, twitter_client_secret) VALUES (?,?,?,?,?)";
              $cordovaSQLite.execute(db, query, [1,'','','','']).then(function(res) {
                  result =  {"twitter_client_secret":"test","instagram_client_id":"","instagram_client_secret":"","twitter_client_id":""};
              });
          }else{
            result = res.rows.item(0);
          }
      });
      return result;
    }
  }
})

And I call my service that way:

requirements = Requirements.get();

But result from $cordovaSQLite.execute(db, query, []).then(function(res){}); isn't the same from the get fuction and I know that my code is executed because I've added console.log() and the app enter in the good part of my code but always return false.

So how can I return the good result please?