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

Faster and Safer Database Queries Using the <CFQUERYPARAM> Tag

Faster and Safer Database Queries Using the <CFQUERYPARAM> Tag

Databases and database access are fundamental elements of just about every ColdFusion application ever created. Database access makes applications real and live and dynamic and valuable, but it's also a major source of performance problems and a primary potential security target. In this article I discuss an oft overlooked tag, <CFQUERYPARAM>, designed to help address both potential problems.

Understanding <CFQUERYPARAM>
Database access (queries, insertions, updates, etc.) occurs by issuing SQL statements - plain text strings containing combinations of special statements, keywords, clauses, operators, and more. These strings are passed to the DBMS for processing (usually via a database driver) and are sometimes referred to as being ad hoc.

So far so good. But this is where it gets a little complicated. There are an infinite number of possible SQL statements (when you take into account the values passed to them), so once a DBMS receives a SQL statement, the DBMS must first analyze it to determine if it's valid, and then work out the best way to process it. Often, the process of parsing, validating, and analyzing the query (the term query refers to all SQL queries, even if they're not SELECT query operations) takes longer than processing the query itself.

Once the query is validated and analyzed, the DBMS tries to cache it so that the process won't need to be repeated unnecessarily. Simple queries without dynamic elements, like the following one, can be cached safely and easily:

SELECT *
FROM Customers

However, queries containing other clauses, like the one that follows, are a little harder to cache. After all, with an infinite number of variations it wouldn't be practical for the DBMS to cache them all:

SELECT *
FROM Customers
WHERE CustID=100

To cache this type of query the DBMS needs to know which part of the statement is dynamic and which is not, and that's where <CFQUERYPARAM> comes into play.

<CFQUERYPARAM> is a tag used within SQL statements (inside your <CFQUERY>). It replaces parameters (or any passed values) with placeholders that indicate the dynamic portions of a statement. For example:

<CFQUERY ...>
SELECT *
FROM Customers
WHERE CustID=<CFQUERYPARAM
CFSQLTYPE="CF_SQL_INTEGER"
VALUE="100">
</CFQUERY>

The <CFQUERYPARAM> tag replaces the passed value (100), and does two things: it defines the type of data that will be passed here and then passes the value to be used.

The actual SQL generated by this query will differ from DBMS to DBMS, but that's somewhat irrelevant. The important thing is that the DBMS knows that the query containing this block of text won't change (and can therefore be cached):

SELECT *
FROM Customers
WHERE CustID=

In DBMSese these variable portions of SQL statements, the ones bookmarked with <CFQUERYPARAM>, are known as bind parameters.

Specifying SQL Types
The data type passed to CFSQLTYPE tells the DBMS to expect data of a particular type. The supported types are:

 

  • CF_SQL_BIGINT
  • CF_SQL_BIT
  • CF_SQL_CHAR
  • CF_SQL_DATE
  • CF_SQL_DECIMAL
  • CF_SQL_DOUBLE
  • CF_SQL_FLOAT
  • CF_SQL_IDSTAMP
  • CF_SQL_INTEGER
  • CF_SQL_LONGVARCHAR
  • CF_SQL_MONEY
  • CF_SQL_MONEY4
  • CF_SQL_NUMERIC
  • CF_SQL_REAL
  • CF_SQL_REFCURSOR
  • CF_SQL_SMALLINT
  • CF_SQL_TIME
  • CF_SQL_TIMESTAMP
  • CF_SQL_TINYINT
  • CF_SQL_VARCHAR

    CFSQLTYPE is an optional at-tribute, but as a rule you should always specify an explicit type. The default value is CF_SQL_CHAR (a string) and is frequently not what you need.

    Increased Performance
    As already implied, the first benefit of using <CFQUERYPARAM> is increased performance. If the DBMS doesn't have to parse, analyze, and validate as much text, it'll be able to respond to requests quicker and more efficiently.

    It's common knowledge that stored procedures execute faster than ad hoc SQL statements. Part of the reason for this is that DBMSs cache the compiled stored procedures so they won't need to be processed repeatedly and unnecessarily. By using <CFQUERYPARAM> you get some of the benefits of stored procedures without having to write one.

    If you're interested in determining what the actual performance benefit is, turn on ColdFusion debugging output and try the queries both ways. As the DBMS load increases, so should the benefit of using bind parameters.

    Protecting from Malicious URL Tampering
    Note: As a rule I'm staunchly opposed to documenting security issues and how they're used, but as this particular vulnerability has been documented extensively (there are even Knowledge Base articles about it at www.macromedia.com) I'm making an exception this time.

    Another benefit to using <CF-QUERYPARAM> is security against malicious URL tampering. Consider the following example, an adaptation of the one used previously:

    SELECT *
    FROM Customers
    WHERE CustID=#URL.custid#

    Here a WHERE clause is populated dynamically using a URL parameter. This type of code is common and popular, and is used any time data drilldown of any kind is used. If the URL was:

    http://domain/path/file.cfm?custid=100

    the resulting SQL statement would be:

    SELECT *
    FROM Customers
    WHERE CustID=100

    But what if someone tampered with that URL so that it read:

    http://domain/path/file.cfm?custid=100;DELETE+Customers

    The resulting SQL would be:

    SELECT *
    FROM Customers
    WHERE CustID=100;
    DELETE Customers

    Depending on the DBMS being used, the <CFQUERY> could end up executing two statements - the SELECT and then DELETE Customers (which would promptly delete all data from the Customers table).

    Scared? You should be. As I mentioned earlier SQL statements are not just used for queries. They're also used to create and drop tables, create user logins, change DBMS passwords, set security levels, manage scheduled events, even create and drop entire databases. All features supported by your DBMS may be accessible this way.

    Before I go further I must point out that this is not a ColdFusion vulnerability; it's not even a bug or a hole. This is truly a feature - many DBMSs do indeed allow queries to contain more than a single operation; this is legal and by design.

    Of course, you should always be checking parameters before passing them to your DBMS. Passing URL parameters through unchecked is programmatic suicide. As such, you should already be using code like this:

    <CFIF IsDefined("URL.CustID")
    AND NOT IsNumeric(URL.CustID)>
    ... throw an error or something ...
    </CFIF>

    But <CFQUERYPARAM> provides one extra line of defense. If the previous tampered URL was passed to the following query, the value would be rejected and an error thrown. The CFSQLTYPE value also doubles as a datatype validation check, and values that don't match the type are rejected. Using <CFQUERYPARAM> you can secure yourself against one of the oldest and best-known hacks in the book.

    Note: This type of hack is one of the reasons you should never configure ColdFusion to use administrative accounts for database access (the SA account, for example). As a rule, the login specified in the data source definition should have just the access it needs and nothing more. If administrative access is not available to a login, then some of the more dangerous commands wouldn't be executable.

    Summary
    <CFQUERYPARAM> is not a new tag; it's been in ColdFusion since version 4.5. However, many developers have yet to use <CFQUERYPARAM>, primarily because they don't understand it. Most good DBMSs (including SQL Server and Oracle) support the use of bind parameters, but some don't. Be sure to read the docs on this tag, and then start plugging it into any new code and even existing apps. With increased performance and improved security you'd be remiss not to.

  • More Stories By Ben Forta

    Ben Forta is Adobe's Senior Technical Evangelist. In that capacity he spends a considerable amount of time talking and writing about Adobe products (with an emphasis on ColdFusion and Flex), and providing feedback to help shape the future direction of the products. By the way, if you are not yet a ColdFusion user, you should be. It is an incredible product, and is truly deserving of all the praise it has been receiving. In a prior life he was a ColdFusion customer (he wrote one of the first large high visibility web sites using the product) and was so impressed he ended up working for the company that created it (Allaire). Ben is also the author of books on ColdFusion, SQL, Windows 2000, JSP, WAP, Regular Expressions, and more. Before joining Adobe (well, Allaire actually, and then Macromedia and Allaire merged, and then Adobe bought Macromedia) he helped found a company called Car.com which provides automotive services (buy a car, sell a car, etc) over the Web. Car.com (including Stoneage) is one of the largest automotive web sites out there, was written entirely in ColdFusion, and is now owned by Auto-By-Tel.

    Comments (7) 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
    fgfrs 05/05/03 03:12:00 PM EDT

    b nv mn m

    Srinivasa 08/22/02 04:02:00 AM EDT
    Mo Hadi 02/13/02 12:07:00 PM EST

    There must be some kind of special set up necessary to do this, because I get the following error when after I change my code to use CFQUERYPARAM. Am I right?

    ODBC Error Code = S1C00 (Driver not capable)

    [Microsoft][ODBC SQL Server Driver]Optional feature not implemented

    David Shadovitz 02/12/02 03:28:00 PM EST

    Oops. CFDJ's code cut out my example CFML. Let's see if this gets through:

    WHERE id IN (<cfqueryparam value="#Form.ID#" cfsqltype="CF_SQL_INTEGER" list="yes">)

    David Shadovitz 02/12/02 03:25:00 PM EST

    As BF mentions, the default value of cfsqltype is CF_SQL_CHAR.

    If you get the error "ODBC Error Code = S1104 (Invalid precision value)", try using CF_SQL_VARCHAR instead.

    David Shadovitz 02/12/02 03:22:00 PM EST

    It's worth mentioning that CFQUERYPARAM can also be used with a list of values:

    ... WHERE ID IN ()

    Brad Howerter 02/12/02 01:06:00 PM EST

    Another benefit of is that you don't have to mess with preserveSingleQuotes().

    @ThingsExpo Stories
    Identity is in everything and customers are looking to their providers to ensure the security of their identities, transactions and data. With the increased reliance on cloud-based services, service providers must build security and trust into their offerings, adding value to customers and improving the user experience. Making identity, security and privacy easy for customers provides a unique advantage over the competition.
    19th Cloud Expo, taking place November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud strategy. Meanwhile, 94% of enterpri...
    Smart Cities are here to stay, but for their promise to be delivered, the data they produce must not be put in new siloes. In his session at @ThingsExpo, Mathias Herberts, Co-founder and CTO of Cityzen Data, will deep dive into best practices that will ensure a successful smart city journey.
    SYS-CON Events announced today that 910Telecom will exhibit at the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Housed in the classic Denver Gas & Electric Building, 910 15th St., 910Telecom is a carrier-neutral telecom hotel located in the heart of Denver. Adjacent to CenturyLink, AT&T, and Denver Main, 910Telecom offers connectivity to all major carriers, Internet service providers, Internet backbones and ...
    There is growing need for data-driven applications and the need for digital platforms to build these apps. In his session at 19th Cloud Expo, Muddu Sudhakar, VP and GM of Security & IoT at Splunk, will cover different PaaS solutions and Big Data platforms that are available to build applications. In addition, AI and machine learning are creating new requirements that developers need in the building of next-gen apps. The next-generation digital platforms have some of the past platform needs a...
    SYS-CON Events announced today Telecom Reseller has been named “Media Sponsor” of SYS-CON's 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Telecom Reseller reports on Unified Communications, UCaaS, BPaaS for enterprise and SMBs. They report extensively on both customer premises based solutions such as IP-PBX as well as cloud based and hosted platforms.
    I wanted to gather all of my Internet of Things (IOT) blogs into a single blog (that I could later use with my University of San Francisco (USF) Big Data “MBA” course). However as I started to pull these blogs together, I realized that my IOT discussion lacked a vision; it lacked an end point towards which an organization could drive their IOT envisioning, proof of value, app dev, data engineering and data science efforts. And I think that the IOT end point is really quite simple…
    Internet of @ThingsExpo, taking place November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 19th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The Internet of Things (IoT) is the most profound change in personal and enterprise IT since the creation of the Worldwide Web more than 20 years ago. All major researchers estimate there will be tens of billions devices - comp...
    DevOps at Cloud Expo, taking place Nov 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 19th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The widespread success of cloud computing is driving the DevOps revolution in enterprise IT. Now as never before, development teams must communicate and collaborate in a dynamic, 24/7/365 environment. There is no time to wait for long dev...
    The 19th International Cloud Expo has announced that its Call for Papers is open. Cloud Expo, to be held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, brings together Cloud Computing, Big Data, Internet of Things, DevOps, Digital Transformation, Microservices and WebRTC to one location. With cloud computing driving a higher percentage of enterprise IT budgets every year, it becomes increasingly important to plant your flag in this fast-expanding business opportuni...
    Data is the fuel that drives the machine learning algorithmic engines and ultimately provides the business value. In his session at Cloud Expo, Ed Featherston, a director and senior enterprise architect at Collaborative Consulting, will discuss the key considerations around quality, volume, timeliness, and pedigree that must be dealt with in order to properly fuel that engine.
    Pulzze Systems was happy to participate in such a premier event and thankful to be receiving the winning investment and global network support from G-Startup Worldwide. It is an exciting time for Pulzze to showcase the effectiveness of innovative technologies and enable them to make the world smarter and better. The reputable contest is held to identify promising startups around the globe that are assured to change the world through their innovative products and disruptive technologies. There w...
    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 business becomes digital the more stakeholders are interested in this data including how it relates to business. Some of these people have never used a monitoring tool before. They have a question on their mind like “How is my application doing” but no id...
    Personalization has long been the holy grail of marketing. Simply stated, communicate the most relevant offer to the right person and you will increase sales. To achieve this, you must understand the individual. Consequently, digital marketers developed many ways to gather and leverage customer information to deliver targeted experiences. In his session at @ThingsExpo, Lou Casal, Founder and Principal Consultant at Practicala, discussed how the Internet of Things (IoT) has accelerated our abil...
    With so much going on in this space you could be forgiven for thinking you were always working with yesterday’s technologies. So much change, so quickly. What do you do if you have to build a solution from the ground up that is expected to live in the field for at least 5-10 years? This is the challenge we faced when we looked to refresh our existing 10-year-old custom hardware stack to measure the fullness of trash cans and compactors.
    The emerging Internet of Everything creates tremendous new opportunities for customer engagement and business model innovation. However, enterprises must overcome a number of critical challenges to bring these new solutions to market. In his session at @ThingsExpo, Michael Martin, CTO/CIO at nfrastructure, outlined these key challenges and recommended approaches for overcoming them to achieve speed and agility in the design, development and implementation of Internet of Everything solutions wi...
    Cloud computing is being adopted in one form or another by 94% of enterprises today. Tens of billions of new devices are being connected to The Internet of Things. And Big Data is driving this bus. An exponential increase is expected in the amount of information being processed, managed, analyzed, and acted upon by enterprise IT. This amazing is not part of some distant future - it is happening today. One report shows a 650% increase in enterprise data by 2020. Other estimates are even higher....
    Is the ongoing quest for agility in the data center forcing you to evaluate how to be a part of infrastructure automation efforts? As organizations evolve toward bimodal IT operations, they are embracing new service delivery models and leveraging virtualization to increase infrastructure agility. Therefore, the network must evolve in parallel to become equally agile. Read this essential piece of Gartner research for recommendations on achieving greater agility.
    SYS-CON Events announced today that Venafi, the Immune System for the Internet™ and the leading provider of Next Generation Trust Protection, will exhibit at @DevOpsSummit at 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Venafi is the Immune System for the Internet™ that protects the foundation of all cybersecurity – cryptographic keys and digital certificates – so they can’t be misused by bad guys in attacks...
    For basic one-to-one voice or video calling solutions, WebRTC has proven to be a very powerful technology. Although WebRTC’s core functionality is to provide secure, real-time p2p media streaming, leveraging native platform features and server-side components brings up new communication capabilities for web and native mobile applications, allowing for advanced multi-user use cases such as video broadcasting, conferencing, and media recording.