Organizing Javascript codes with namespacing

Usually when I build website each page has it's own Javascript file. But as the site grows I find it hard to maintain and code duplication is every where. After a few googling and research I found out that Javacript namespacing is the best way to organize and modularize your code. With my current hybrid app I have to constantly communicate with SQLite and that's how I realize I have to reuse code blocks to avoid spaghetti code. What I did is something like this.

Let's break it down into pieces.

• Line one - we create a closure and import jQuery object so we can use it inside our namespace. You can remove the dollar sign ($) if you don't need it. Make sure you remove 'jQuery' at line 25 too.
• Line two - we declare a global object variable 'APP'. This is our namespace.
• Line four - we put a sub-namespace called SQL. Basically this a namespace inside a namespace. cool isn't.
• Line 5 - we declare a function named 'insert' with parameter 'data'. We can now call this function by calling our namespace and it's sub-namespace like this: APP.SQL.insert(mydata);
• We can put any number of functions inside our namespace, remember to put comma in between function just like what we did on line eight.
• Line fifteen - We declare another sub-namespace called 'HELPER'. The list can go on as much as you need

 We are now ready to include our js file in every page that need it. Our code is now more readable and in groups for easier maintenance and debugging. Our code is also somewhat modularize and reusable. Any suggestion, improvements, errors you found, please comment below.