Can't get an alert() to fire on successfully posting to database

I am learning how to use a backend so forgive me if this is elementary, it seems like I'm missing something simple. I am trying to create a simple CRUD app to learn so I chose to make a blog platform that I can incorporate into my website later.

I am using Angular, Node and Express, and PostgreSql.

I can successfully post entries into the database. I can see them on Postico when I click Enter. I just can't seem to figure out how to fire an alert that notifies if the entry was posted successfully or not. Right now I have the alert in the Angular service on a .success etc, but I have a feeling that's wrong. When I was searching for the answer here other people had it in the controller but I tried that and it didn't work.

Here's the relevant code I have:

createEntry.html

  <form ng-submit="createBlogEntry(blog)">
  <h2>Title:</h2>
      <input type="title" ng-model="blog.title"></input>
    <br>
  <h3>Author:</h3>
      <input type="author" ng-model="blog.author"></input>
    <br>
  <h3>Photo:</h3>
      <input type="imageUrl" ng-model="blog.imageUrl"></input>
    <br>
  <h3>Content:</h3>
    <textarea type="content" rows="5" cols="50" ng-model="blog.content">
    </textarea>
    <br>
  <button type="submit">Save Entry</button>
  </form>

createEntryCtrl.js The angular controller

angular.module("blog").controller("createEntryCtrl", function($scope, adminService) {

    $scope.createBlogEntry = function(blog){
        adminService.createBlogEntry(blog);
    }

});

adminService.js The Angular service:

angular.module("blog").service("adminService", function($http) {

this.createBlogEntry = function(blog) {

$http.post('/api/createBlogEntry', blog)
    .success(function(data) {
      alert("Entry Posted");
    })
    .error(function(data) {
      alert("Error in Posting");
    })
  }

});

index.js The Server Index (minus irrelevant endpoints)

// EXTERNAL MODULES //
var express = require('express');
var bodyParser = require('body-parser');
var session = require('express-session');
var massive = require('massive');

// CONFIG //
var config = require('./config');

// EXPRESS //
var app = module.exports = express();

app.use(express.static(__dirname + './../dist'));
app.use(bodyParser.json());

// MASSIVE //
var massiveUri = config.MASSIVE_URI;
var massiveServer = massive.connectSync({
    connectionString: massiveUri
});
app.set('db', massiveServer);
var db = app.get('db');

var dbSetup = require('./services/dbSetup');
dbSetup.run(); 

// CONTROLLERS //
var userCtrl = require('./controllers/userCtrl');
var blogCtrl = require('./controllers/blogCtrl');

// Blog Endpoints //
app.post('/api/createBlogEntry', blogCtrl.createBlogEntry);

// CONNECTIONS //
var port = config.PORT;
app.listen(port, function() {
    console.log('Listening on port ' + port);
});

blogCtrl.js Node Controller:

var app = require('./../index');
var db = app.get('db');

module.exports = {

createBlogEntry: function(req, res, next) {
    console.log(res);
    var blog = req.body;
    db.blogs.blog_create([blog.title, blog.author, blog.imageUrl, blog.content], function(err, blog) {
        if (err) {
            return res.status(500).send(err);
        }
    })
  }

};

blog_create.sql The Sql:

INSERT INTO blogs (title, author, imageUrl, content)
VALUES ($1, $2, $3, $4)

via Diego