Welcome!

You will be redirected in 30 seconds or close now.

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

Related Topics: ColdFusion

ColdFusion: Article

Generic SQL Table Export

Generic SQL Table Export

In my last article (CFDJ, Vol. 1, issue 6) I presented Array_Table, a universal browser-based table viewer and query engine. Array_Table allows you to browse, edit and query any Microsoft SQL Server table. It's 100% dynamic so it works with any database.

Many readers and clients loved the new capability and ease it offered. And they wanted more, of course.

Feeling Trapped?
Most data-driven Web sites are located on remote servers. If you use a server-based database like Microsoft SQL Server, it's difficult to retrieve table data locally. Downloading entire tables for use with your desktop software or to keep a local backup seems impossible. In addition, your end users may periodically need to download data from the data-driven sites you create.

Freedom At Last!
We're going to add generic table export capability to Array_Table. It'll allow you to generate a common, popular and generic text file that can be used in almost any desktop application or database. Array_Export will create a text file and optionally e-mail it to you. With this functionality you'll have the freedom to actually get to your data. You can see Array_Table and Array_Export in action at www. arrayone.com/Table/.Do_it! To present your users with a list of available tables, I created Table_List.cfm (see Figure 1).

This form shows you a list of all the tables in a data source with the option to view the data or query the table. I've added a choice, "Export", to the table list. This is the only necessary addition to Table_List.cfm (see Listing 1) and it's simply a hot link to the table export program. Here's the code.... <a href="Export/Export_Menu.cfm?TableName=#Table_List.Name#">Export</a>

All of the export files are being stored and called from a subfolder, "Export". This keeps your files neat and provides one point of reference if you have to modify any export-related code.

When you click on "Export", the Export_menu.cfm script is called and you're presented with the export menu (see Figure 2 and Listing 2).

The table you selected is automatically passed to the export menu. Now you have the option of exporting the data to a comma- or tab-delimited file, with or without field names in the file header.

If you enter your e-mail address, Array_Export will e-mail the exported data file to you.

How'd He Do That?
It's easier than you think. Array_Export.cfm calls Export.Cfm (see Listing 3). Export.Cfm passes the tablename along with your export selections from the menu to the main ColdFusion script, Table_Export.cfm (see Listing 4). This script handles all the export functionality. Let's examine Export.Cfm.

<!--- Export.CFM - Passes logon and user choice parameters to the export engine, Table_Export.CFM. --->
<!--- Set export file name --->
<cfset Dir_Name = #getdirectory
frompath(gettemplatepath())#>
<cfset FileName = "#Dir_Name#\Data\#TableName##DateFormat("#Now()#","mmddyyyy")#.txt">
<!--- Call export engine --->
<cf_Table_Export
DSN="Demo"
Username="Guest"
Password="Guest"
Table="#TableName#"
FileName="#FileName#"
Delimiter="#Form.Delimiter#"
ColumnHeader="#Form.ColumnHeader#"
Email="#Form.Email#">

Export.cfm sets the directory where the exported data file will be stored. Then it sets the name of the exported file to be the file name plus the current date. So if you were exporting a table called "Sales" on December 6, 1999, the exported file name would be "Sales12061999.txt". Export.cfm then calls Table_Export.

cfm and passes all the necessary parameters, such as tablename and filename.

Table_Export.Cfm There are four steps in exporting the table:

1. Query the table to retrieve all of the rows. 3. Write the data out to a text file in delimited text.
4. Mail the exported file to the user.
Step 1. Query the table.

<cfquery name="Export" datasource="Demo" username="Guest" password="Guest">
Select * from #Attributes.Table#
</cfquery>
<cfif Export.RecordCount EQ 0>
There are no records to export
<cfabort>
</cfif>

Simply query the table for all records. If there are none, display a message to the user and abort. If there are, we go to the second step.

Step 2. Get a list of all fields.

<cfquery name="Field_List" datasource="Demo" username="Guest" password="Guest">
SELECT syscolumns.Name
FROM sysobjects , syscolumns
WHERE syscolumns.id = sysobjects.ID
AND upper(sysobjects.Name) = '#Attributes.Table#'
</cfquery>
<!--- Put field list into an array --->
<cfset x = "">
<cfloop query="Field_List">
<cfset x = x & Field_List.Name>
<cfif Field_List.CurrentRow NEQ Field_List.RecordCount>
<cfset x = x & Attributes.Delimiter>
</cfif>
</cfloop>

Here we query the SQL Server system tables (see December 1999 article) to retrieve the list of fieldnames in the table. We need the field list so we can export the data and separate it by fields. The variable x will hold the list of fields, each fieldname separated by a comma.

<Cffile> is the perfect tag for creating and editing text files. Using the action="write" option, ColdFusion will create the text file if it doesn't already exist.

<!--- Create export file --->
<cffile action="WRITE" file="#Attri-butes.FileName#" output=""
addnewline="No">

Once the file is created, you can write the field list header to it (if the user chose to add fieldnames to the file).

<cffile action="APPEND" file="#Attributes.FileName#" output="#x##Chr(13)##Chr(10)#" addnewline="No">

Here, the variable x, which now holds the list of fields, is used.

Step 3. Write the data out to a text file in delimited text.

To make it easier to loop through the list of fields, I prefer to use arrays. The following command converts the fieldlist to an array called FL.

<cfset FL = ListToArray(x, #Attributes. Delimiter#)>

A simple nested (double) loop can now be used to loop through all the records in the table and output all the data. During the loop a single line of data is created in the variable D. It contains all data from all fields as well as the field delimiter character. After the data line is built, it can be written to the text file using <cffile> with the action="append". Append adds new lines to the file without erasing any existing data.

<!--- Loop through the export query which contains all data rows --->
<cfloop query="Export">
<cfset d = "">
<!--- Now loop through the field list and build the row export data --->
<cfloop index="n" from="1" to="#ArrayLen(FL)#">
<cfset S = SetVariable("S", "#FL[n]#")>
<cfset d = d & Trim(#Evaluate(S)#)>
<cfif n NEQ ArrayLen(FL)>
<cfset d = d & Attributes.Delimiter>
</cfif>
</cfloop>
<!--- Write record to text file --->
<cffile action="APPEND" file="#Attributes.FileName#"
input="#d##Chr(13)##Chr(10)#"
addnewline="no">
</cfloop>

Step 4. Mail the exported file to the user.

After the export loop completes the file, a new export file will be sitting on the server. If the user entered an e-mail address on the Export_menu.cfm form, the file will automatically be e-mailed to them. It doesn't get any easier than this.

Extension Cord, Please
Now you have a scalable, dynamic tool to view, query and export data from any table. With the new data export capability it's easy to bring data back to your desktop for backup or manipulation. Since the export generates pure text files, the data can be used in virtually any application. The possibilities are still endless.

More Stories By David Schwartz

David Schwartz is the president of Array Software Inc., a New Jersey-based software company. Array creates global data-driven Internet and intranet Web sites using ColdFusion, Oracle, MS SQL Server and Java. David has been developing turnkey custom database software for 14 years.

Comments (0)

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.


IoT & Smart Cities Stories
Nicolas Fierro is CEO of MIMIR Blockchain Solutions. He is a programmer, technologist, and operations dev who has worked with Ethereum and blockchain since 2014. His knowledge in blockchain dates to when he performed dev ops services to the Ethereum Foundation as one the privileged few developers to work with the original core team in Switzerland.
René Bostic is the Technical VP of the IBM Cloud Unit in North America. Enjoying her career with IBM during the modern millennial technological era, she is an expert in cloud computing, DevOps and emerging cloud technologies such as Blockchain. Her strengths and core competencies include a proven record of accomplishments in consensus building at all levels to assess, plan, and implement enterprise and cloud computing solutions. René is a member of the Society of Women Engineers (SWE) and a m...
Andrew Keys is Co-Founder of ConsenSys Enterprise. He comes to ConsenSys Enterprise with capital markets, technology and entrepreneurial experience. Previously, he worked for UBS investment bank in equities analysis. Later, he was responsible for the creation and distribution of life settlement products to hedge funds and investment banks. After, he co-founded a revenue cycle management company where he learned about Bitcoin and eventually Ethereal. Andrew's role at ConsenSys Enterprise is a mul...
Whenever a new technology hits the high points of hype, everyone starts talking about it like it will solve all their business problems. Blockchain is one of those technologies. According to Gartner's latest report on the hype cycle of emerging technologies, blockchain has just passed the peak of their hype cycle curve. If you read the news articles about it, one would think it has taken over the technology world. No disruptive technology is without its challenges and potential impediments t...
If a machine can invent, does this mean the end of the patent system as we know it? The patent system, both in the US and Europe, allows companies to protect their inventions and helps foster innovation. However, Artificial Intelligence (AI) could be set to disrupt the patent system as we know it. This talk will examine how AI may change the patent landscape in the years to come. Furthermore, ways in which companies can best protect their AI related inventions will be examined from both a US and...
In his general session at 19th Cloud Expo, Manish Dixit, VP of Product and Engineering at Dice, discussed how Dice leverages data insights and tools to help both tech professionals and recruiters better understand how skills relate to each other and which skills are in high demand using interactive visualizations and salary indicator tools to maximize earning potential. Manish Dixit is VP of Product and Engineering at Dice. As the leader of the Product, Engineering and Data Sciences team at D...
Bill Schmarzo, Tech Chair of "Big Data | Analytics" of upcoming CloudEXPO | DXWorldEXPO New York (November 12-13, 2018, New York City) today announced the outline and schedule of the track. "The track has been designed in experience/degree order," said Schmarzo. "So, that folks who attend the entire track can leave the conference with some of the skills necessary to get their work done when they get back to their offices. It actually ties back to some work that I'm doing at the University of San...
When talking IoT we often focus on the devices, the sensors, the hardware itself. The new smart appliances, the new smart or self-driving cars (which are amalgamations of many ‘things'). When we are looking at the world of IoT, we should take a step back, look at the big picture. What value are these devices providing. IoT is not about the devices, its about the data consumed and generated. The devices are tools, mechanisms, conduits. This paper discusses the considerations when dealing with the...
Bill Schmarzo, author of "Big Data: Understanding How Data Powers Big Business" and "Big Data MBA: Driving Business Strategies with Data Science," is responsible for setting the strategy and defining the Big Data service offerings and capabilities for EMC Global Services Big Data Practice. As the CTO for the Big Data Practice, he is responsible for working with organizations to help them identify where and how to start their big data journeys. He's written several white papers, is an avid blogge...
Dynatrace is an application performance management software company with products for the information technology departments and digital business owners of medium and large businesses. Building the Future of Monitoring with Artificial Intelligence. Today we can collect lots and lots of performance data. We build beautiful dashboards and even have fancy query languages to access and transform the data. Still performance data is a secret language only a couple of people understand. The more busine...