Click here to close now.


You will be redirected in 30 seconds or close now.

ColdFusion Authors: Yakov Fain, Maureen O'Gara, Nancy Y. Nee, Tad Anderson, Daniel Kaar

Related Topics: ColdFusion

ColdFusion: Article

Building a Zip Code Proximity Search with ColdFusion

The new challenges and possibilities are numerous

Recently I was tasked with improving our Web site's Reseller Locator application. This tool helps potential customers in the U.S. find a product reseller in their state. By choosing a state from a drop-down box, a listing of all resellers located in that state is displayed.

Over the years, as more and more resellers have signed on to sell our products, some problems with this application have surfaced:

  • Some states, such as California, display a very long list of resellers, and customers may never contact those listed near the bottom.
  • The states with smaller populations such as North Dakota may not have any resellers to list.
  • Competitors could use the tool to easily find all our resellers, and may steal these valuable partner relationships.
The Solution Is Defined
We needed a solution to solve these problems, and searching by zip codes appeared to be the answer. The new tool would ask the customer to enter their five digit zip code in a text box and select a search radius of 25, 50, or 100 miles. We wanted to limit the search to 100 miles, to keep the results to an appropriate number and prevent our competitors from entering 2,000 miles and getting a huge list all at once. For example, I might search for all resellers within 50 miles of 55113. This time a list of resellers in close proximity to St. Paul, MN, is displayed, ignoring those 200 miles north in the city of Duluth. Implementing this approach addressed each problem, respectively:
  • A shorter list would result from the search, containing only the resellers located near the customer's zip code.
  • The list can cross state boundaries, now that it will find all resellers located within the specified radius to the customer, and hopefully would show results for zip codes in states like North Dakota.
  • Competitors can still use the tool to find our resellers, but they'll have to work much harder to get the information with the 100 mile limit.
The "Webmonkey" Demo
I've used many store locator Web applications, such as finding the nearest Quiznos or Best Buy, and always wondered how they worked. Now I had the opportunity to learn something brand new, and I began my quest for how to accomplish the Reseller Locator zip code search by starting where everybody does: Google! I quickly found a great tutorial article with sample ColdFusion code on The article was written by Robert Capili and titled Proximity Searches for Fun and Profit. The stars were aligned that day, since Robert published his article three weeks before I started my project. It was perfect timing, because as I started reading, it became apparent that this was exactly what I needed to get my feet wet. In the article Robert discusses four primary ways to calculate zip code proximities:
  1. Pythagorean Theorem (remember this trig equation? a2 + b2 = c2)
  2. Spherical Law of Cosines (Pythagorean theorem for triangles drawn on a sphere)
  3. Haversine Formula (most accurate way to calculate distance on a sphere)
  4. Square Search (Robert's speedy solution)
For each method, he explains some background information, how it calculates results, how it performs (speed versus accuracy), and his usage suggestions. I encourage you to read it when you finish this article (or now if you feel the need) to dive deeper into this topic: In a nutshell, Robert recommends method #4. He improved upon the speed produced by the Pythagorean method and developed the Square Search. It performs the fastest, but does not take into account the spherical shape of the earth, which the Haversine formula is best at. However, as long as you are not in need of absolute pinpoint accuracy, the Square Search is the way to go for most applications.

Testing the Sample Code
Included in the sample code is a ColdFusion Component, zipfinder.cfc, that implements each of the four search methods. It also contains a testing template, zip.cfm, that has a basic search form, containing a zip code text box and radius text box. Finally, it contains a database file, zipDB. My first step to getting set up was a quick visit to our company's DB Admin, who helped me perform a restore of the SQL database file, zipDB. The database restore creates a single table that contains 29,470 zip code records. Next, I opened Application.cfm and modified the variable application.dsn to use the correct value for our datasource name. Now on to some real testing. I pointed my browser to the zip.cfm template and saw the search form. After entering a zip code and radius in the text boxes, what you get are four cfdumps of the recordsets returned from the CFC, as well as the execution times. Each query gets the city, state, zip code, and distance from the specified zip code. Table 1 and Table 2 show the partial output from a search of 55113.

I soon realized why he recommended the Square Search. The execution time was faster than each of the other methods, and the distance results were very close to the Haversine Formula. After a few more tests, it was soon time to put the final pieces together.

Integrating the Solution
Now I needed to take the recordset returned by the Square Search method and put it to use in my application. We have a database table (actually a view) of resellers that includes the field: zipcode. Nothing special here; most of us are familiar with SQL tables that contain address information broken out in separate fields. All I needed to do was create a new query against the reseller table, and make sure a reseller's zip code was found among the zip codes in the recordset returned by the CFC. The code and query looked like this:

<cfinvoke component="zipfinder" method="squareSearch" radius="#URL.miles#"
zip="" returnvariable="results"></cfinvoke>

<cfif NOT results.recordcount>
   Sorry, no zip codes found within #URL.miles# miles of

<cfquery name="get_resellers" datasource="#dsn#">
select *
from PartnerView
where zipcode IN (#ListQualify(ValueList(,"'")#)
and Country = 'USA'
order by CompanyName

The first block of code invokes the CFC, calling the SquareSearch method. Next, I verify at least one record is returned. If not, I stop right there and let the user know with a friendly error message. Last, I perform a search against our resellers, using the clause:

where zipcode IN (#ListQualify(ValueList(,"'")#)

Based on the sample records I listed earlier, the actual query might look like:

select *
from PartnerView
where zipcode IN ('55113','55108','55117','55103','55114','55104','55414','55101','55418')
and Country = 'USA'
order by CompanyName

The ListQualify() and ValueList() ColdFusion functions come in handy here. ValueList() converts a query column into a comma-delimited list, then ListQualify() slaps a single quote around each item in the list. This is exactly what is needed to use as the expression on the right-hand side of the IN clause. All that's left is to display the results from the get_resellers query in a nice HTML format, and the customer has the information he or she needs to make a couple of phone calls that will hopefully lead to a future sale!

More Stories By Troy Pullis

Troy Pullis works as a senior Web developer for Secure Computing Corporation ( and also manages the Twin Cities ColdFusion Users Group ( He is a Certified Advanced CFMX Developer. Back in 1999, Troy shifted his client/server Java programming career to focus on the Internet boom. He immediately started using ColdFusion, began attending CFUG meetings, and has never looked back.

Comments (3) View Comments

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.

Most Recent Comments
CFDJ News Desk 12/15/05 06:33:24 PM EST

Building a Zip Code Proximity Search with ColdFusion. Recently I was tasked with improving our Web site's Reseller Locator application. This tool helps potential customers in the U.S. find a product reseller in their state. By choosing a state from a drop-down box, a listing of all resellers located in that state is displayed.

CFDJ News Desk 12/15/05 06:03:25 PM EST

Building a Zip Code Proximity Search with ColdFusion. Recently I was tasked with improving our Web site's Reseller Locator application. This tool helps potential customers in the U.S. find a product reseller in their state. By choosing a state from a drop-down box, a listing of all resellers located in that state is displayed.

@ThingsExpo Stories
Just over a week ago I received a long and loud sustained applause for a presentation I delivered at this year’s Cloud Expo in Santa Clara. I was extremely pleased with the turnout and had some very good conversations with many of the attendees. Over the next few days I had many more meaningful conversations and was not only happy with the results but also learned a few new things. Here is everything I learned in those three days distilled into three short points.
As organizations realize the scope of the Internet of Things, gaining key insights from Big Data, through the use of advanced analytics, becomes crucial. However, IoT also creates the need for petabyte scale storage of data from millions of devices. A new type of Storage is required which seamlessly integrates robust data analytics with massive scale. These storage systems will act as “smart systems” provide in-place analytics that speed discovery and enable businesses to quickly derive meaningful and actionable insights. In his session at @ThingsExpo, Paul Turner, Chief Marketing Officer at...
DevOps is about increasing efficiency, but nothing is more inefficient than building the same application twice. However, this is a routine occurrence with enterprise applications that need both a rich desktop web interface and strong mobile support. With recent technological advances from Isomorphic Software and others, rich desktop and tuned mobile experiences can now be created with a single codebase – without compromising functionality, performance or usability. In his session at DevOps Summit, Charles Kendrick, CTO and Chief Architect at Isomorphic Software, demonstrated examples of com...
In his General Session at 17th Cloud Expo, Bruce Swann, Senior Product Marketing Manager for Adobe Campaign, explored the key ingredients of cross-channel marketing in a digital world. Learn how the Adobe Marketing Cloud can help marketers embrace opportunities for personalized, relevant and real-time customer engagement across offline (direct mail, point of sale, call center) and digital (email, website, SMS, mobile apps, social networks, connected objects).
The Internet of Everything is re-shaping technology trends–moving away from “request/response” architecture to an “always-on” Streaming Web where data is in constant motion and secure, reliable communication is an absolute necessity. As more and more THINGS go online, the challenges that developers will need to address will only increase exponentially. In his session at @ThingsExpo, Todd Greene, Founder & CEO of PubNub, exploreed the current state of IoT connectivity and review key trends and technology requirements that will drive the Internet of Things from hype to reality.
Two weeks ago (November 3-5), I attended the Cloud Expo Silicon Valley as a speaker, where I presented on the security and privacy due diligence requirements for cloud solutions. Cloud security is a topical issue for every CIO, CISO, and technology buyer. Decision-makers are always looking for insights on how to mitigate the security risks of implementing and using cloud solutions. Based on the presentation topics covered at the conference, as well as the general discussions heard between sessions, I wanted to share some of my observations on emerging trends. As cyber security serves as a fou...
Continuous processes around the development and deployment of applications are both impacted by -- and a benefit to -- the Internet of Things trend. To help better understand the relationship between DevOps and a plethora of new end-devices and data please welcome Gary Gruver, consultant, author and a former IT executive who has led many large-scale IT transformation projects, and John Jeremiah, Technology Evangelist at Hewlett Packard Enterprise (HPE), on Twitter at @j_jeremiah. The discussion is moderated by me, Dana Gardner, Principal Analyst at Interarbor Solutions.
Too often with compelling new technologies market participants become overly enamored with that attractiveness of the technology and neglect underlying business drivers. This tendency, what some call the “newest shiny object syndrome” is understandable given that virtually all of us are heavily engaged in technology. But it is also mistaken. Without concrete business cases driving its deployment, IoT, like many other technologies before it, will fade into obscurity.
The Internet of Things is clearly many things: data collection and analytics, wearables, Smart Grids and Smart Cities, the Industrial Internet, and more. Cool platforms like Arduino, Raspberry Pi, Intel's Galileo and Edison, and a diverse world of sensors are making the IoT a great toy box for developers in all these areas. In this Power Panel at @ThingsExpo, moderated by Conference Chair Roger Strukhoff, panelists discussed what things are the most important, which will have the most profound effect on the world, and what should we expect to see over the next couple of years.
With all the incredible momentum behind the Internet of Things (IoT) industry, it is easy to forget that not a single CEO wakes up and wonders if “my IoT is broken.” What they wonder is if they are making the right decisions to do all they can to increase revenue, decrease costs, and improve customer experience – effectively the same challenges they have always had in growing their business. The exciting thing about the IoT industry is now these decisions can be better, faster, and smarter. Now all corporate assets – people, objects, and spaces – can share information about themselves and thei...
PubNub has announced the release of BLOCKS, a set of customizable microservices that give developers a simple way to add code and deploy features for realtime apps.PubNub BLOCKS executes business logic directly on the data streaming through PubNub’s network without splitting it off to an intermediary server controlled by the customer. This revolutionary approach streamlines app development, reduces endpoint-to-endpoint latency, and allows apps to better leverage the enormous scalability of PubNub’s Data Stream Network.
I recently attended and was a speaker at the 4th International Internet of @ThingsExpo at the Santa Clara Convention Center. I also had the opportunity to attend this event last year and I wrote a blog from that show talking about how the “Enterprise Impact of IoT” was a key theme of last year’s show. I was curious to see if the same theme would still resonate 365 days later and what, if any, changes I would see in the content presented.
Apps and devices shouldn't stop working when there's limited or no network connectivity. Learn how to bring data stored in a cloud database to the edge of the network (and back again) whenever an Internet connection is available. In his session at 17th Cloud Expo, Ben Perlmutter, a Sales Engineer with IBM Cloudant, demonstrated techniques for replicating cloud databases with devices in order to build offline-first mobile or Internet of Things (IoT) apps that can provide a better, faster user experience, both offline and online. The focus of this talk was on IBM Cloudant, Apache CouchDB, and ...
Microservices are a very exciting architectural approach that many organizations are looking to as a way to accelerate innovation. Microservices promise to allow teams to move away from monolithic "ball of mud" systems, but the reality is that, in the vast majority of organizations, different projects and technologies will continue to be developed at different speeds. How to handle the dependencies between these disparate systems with different iteration cycles? Consider the "canoncial problem" in this scenario: microservice A (releases daily) depends on a couple of additions to backend B (re...
There are over 120 breakout sessions in all, with Keynotes, General Sessions, and Power Panels adding to three days of incredibly rich presentations and content. Join @ThingsExpo conference chair Roger Strukhoff (@IoT2040), June 7-9, 2016 in New York City, for three days of intense 'Internet of Things' discussion and focus, including Big Data's indespensable role in IoT, Smart Grids and Industrial Internet of Things, Wearables and Consumer IoT, as well as (new) IoT's use in Vertical Markets.
Discussions of cloud computing have evolved in recent years from a focus on specific types of cloud, to a world of hybrid cloud, and to a world dominated by the APIs that make today's multi-cloud environments and hybrid clouds possible. In this Power Panel at 17th Cloud Expo, moderated by Conference Chair Roger Strukhoff, panelists addressed the importance of customers being able to use the specific technologies they need, through environments and ecosystems that expose their APIs to make true change and transformation possible.
Container technology is shaping the future of DevOps and it’s also changing the way organizations think about application development. With the rise of mobile applications in the enterprise, businesses are abandoning year-long development cycles and embracing technologies that enable rapid development and continuous deployment of apps. In his session at DevOps Summit, Kurt Collins, Developer Evangelist at, examined how Docker has evolved into a highly effective tool for application delivery by allowing increasingly popular Mobile Backend-as-a-Service (mBaaS) platforms to quickly crea...
The Internet of Things (IoT) is growing rapidly by extending current technologies, products and networks. By 2020, Cisco estimates there will be 50 billion connected devices. Gartner has forecast revenues of over $300 billion, just to IoT suppliers. Now is the time to figure out how you’ll make money – not just create innovative products. With hundreds of new products and companies jumping into the IoT fray every month, there’s no shortage of innovation. Despite this, McKinsey/VisionMobile data shows "less than 10 percent of IoT developers are making enough to support a reasonably sized team....
The cloud. Like a comic book superhero, there seems to be no problem it can’t fix or cost it can’t slash. Yet making the transition is not always easy and production environments are still largely on premise. Taking some practical and sensible steps to reduce risk can also help provide a basis for a successful cloud transition. A plethora of surveys from the likes of IDG and Gartner show that more than 70 percent of enterprises have deployed at least one or more cloud application or workload. Yet a closer inspection at the data reveals less than half of these cloud projects involve production...
Internet of @ThingsExpo, taking place June 7-9, 2016 at Javits Center, New York City and Nov 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with the 18th International @CloudExpo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world and ThingsExpo New York Call for Papers is now open.