[x]
Posted via EE Mobile

Search, ask, and monitor your questions on the go with EE Mobile. Visit Experts Exchange from your mobile device and never be out of touch again.
Question
[x]
Attachment Details
[x]
The Solution Rating System

With so many solutions, how can you tell which solutions are most likely to help you and which ones are not? To provide you with a tool to use, we rate our solutions based on various elements that most accurately determine if a solution is a quality solution. To explain what factors affect the solution rating, here are the elements we take into consideration when formulating our solution rating.

  • The Grade of the Solution
  • The Zone Rank of the Expert Providing the Solution
  • The Number of Author and Expert Comments
  • The Number of Experts Contributing
  • The Feedback of the Community

Your Input Matters
Because of the way the system is set up, the most important variable in this equation is you. As a member of Experts Exchange, you are able to cast your vote on the quality of the solutions in regard to how complete, accurate, helpful and easy to understand each solution is. When you provide your feedback, each rating is adjusted accordingly. So, if you see a solution that has a poor rating that you think is a good solution, let us know by rating it. As you do, the rating will be adjusted and will become more accurate for other members of our site.

If you have any suggestions that you would like to make for our rating system, please ask a question in the Suggestions Zone of Community Support.

Thank you!
7.0

For Experts: Differences between VB and Jet expressions

Asked by harfang in Microsoft Access Database

Tags: Microsoft, Access

Hello experts,

This is not really a question, but rather a open thread for technical discussion. However, points will be awarded for good explanations and original examples (see below).

I just lost one day hunting a bug in an application I'm working on. I quickly found the origin, but at first failed to correct the bug by introducing a new one. Consider the following query.

    UPDATE Table1 SET OK=IIf(Something,True,False)

The idea: set the OK flag for those records where 'Something' is both not null and not zero. Note that a previous version using Nz() caused the original bug, which I'm not going into. I'm also not expanding on why I would want to store a derived information like this (it had to do with optimization; let's leave it at that).

The problem: IIf(), when interpreted by Jet, does not work *exactly* like VB's IIf(). Since we all know that Eval() implements Jet's expression evaluator, we can test the following from the immediate pane:

    ? IIf(0.1,True,False)
    True
    ? Eval("IIf(0.1,True,False)")
    0

For VB, 0.1 is of course 'True', being non-zero. But apparently, 0.1 is 'False' for Jet, meaning that the argument is probably first cast to a Variant Integer (or a Variant Boolean) before being evaluated.

Another such difference between VB and Jet can be discovered by comparing:

    ? 3 And 7
     3
    ? Eval("3 And 7")
    -1

This has already been discussed in a previous Expert thread: {http:/Q_22135795.html}. Other known differences are that Jet allows single quotes, does not parse VB type-definition characters, and implements additional SQL operators.

So, the questions are:

    * Can you explain why IIf() behaves differently between Jet and VB?

    * Is this a bug or a feature?

    * Do you have other examples of such differences?

The question is *not*:

    * How to make this query work as expected?

But if course, feel free to experiment and share if you want.

Cheers all!

Markus
(°v°)
Related Solutions: For Experts: Exploring the DAO object modelFor Experts: Obfuscated Access Contest
[+][-]07/02/08 04:50 PM, ID: 21921790Expert Comment

At Experts Exchange, members can ask their questions to thousands of technology professionals, also known as Experts. Experts compete and collaborate to answer those questions by leaving comments like this one.

Start your 30-day free trial to view this Expert Comment or ask the Experts your question.

 
[+][-]07/02/08 04:54 PM, ID: 21921806Author Comment

Often, when Experts are collaborating with members who have asked questions, they will request additional information about the problem. Askers respond with an author comment like this one.

Start your 30-day free trial to view this Author Comment or ask the Experts your question.

 
[+][-]07/02/08 06:41 PM, ID: 21922138Administrative Comment

Experts Exchange has a courteous staff of administrators who help members get the most out of the website by means of administrative comments like this one.

Start your 30-day free trial to view this Administrative Comment or ask the Experts your question.

 
[+][-]07/02/08 06:44 PM, ID: 21922149Assisted Solution

Assisted solutions are selected by the member who asked the question as a comment that contributed to their question's solution.

Start your 30-day free trial to view this Assisted Solution or ask the Experts your question.

 
[+][-]07/02/08 07:00 PM, ID: 21922195Assisted Solution

Assisted solutions are selected by the member who asked the question as a comment that contributed to their question's solution.

Start your 30-day free trial to view this Assisted Solution or ask the Experts your question.

 
[+][-]07/02/08 07:03 PM, ID: 21922207Expert Comment

At Experts Exchange, members can ask their questions to thousands of technology professionals, also known as Experts. Experts compete and collaborate to answer those questions by leaving comments like this one.

Start your 30-day free trial to view this Expert Comment or ask the Experts your question.

 
[+][-]07/02/08 09:26 PM, ID: 21922679Expert Comment

At Experts Exchange, members can ask their questions to thousands of technology professionals, also known as Experts. Experts compete and collaborate to answer those questions by leaving comments like this one.

Start your 30-day free trial to view this Expert Comment or ask the Experts your question.

 
[+][-]07/02/08 09:59 PM, ID: 21922757Expert Comment

At Experts Exchange, members can ask their questions to thousands of technology professionals, also known as Experts. Experts compete and collaborate to answer those questions by leaving comments like this one.

Start your 30-day free trial to view this Expert Comment or ask the Experts your question.

 
[+][-]07/02/08 10:11 PM, ID: 21922786Assisted Solution

Assisted solutions are selected by the member who asked the question as a comment that contributed to their question's solution.

Start your 30-day free trial to view this Assisted Solution or ask the Experts your question.

 
[+][-]07/02/08 10:24 PM, ID: 21922833Assisted Solution

Assisted solutions are selected by the member who asked the question as a comment that contributed to their question's solution.

Start your 30-day free trial to view this Assisted Solution or ask the Experts your question.

 
[+][-]07/03/08 12:51 AM, ID: 21923476Assisted Solution

Assisted solutions are selected by the member who asked the question as a comment that contributed to their question's solution.

Start your 30-day free trial to view this Assisted Solution or ask the Experts your question.

 
[+][-]07/03/08 03:51 AM, ID: 21924110Author Comment

Often, when Experts are collaborating with members who have asked questions, they will request additional information about the problem. Askers respond with an author comment like this one.

Start your 30-day free trial to view this Author Comment or ask the Experts your question.

 
[+][-]07/03/08 04:26 AM, ID: 21924328Accepted Solution

View this solution now by starting your 30-day free trial. Setting up your free trial is quick, easy, and secure. We will return you to this solution, unlocked, when you're done.

About this solution

Zone: Microsoft Access Database
Tags: Microsoft, Access
Sign Up Now!
Solution Provided By: cactus_data
Participating Experts: 6
Solution Grade: A
 
[+][-]07/03/08 09:12 AM, ID: 21926864Expert Comment

At Experts Exchange, members can ask their questions to thousands of technology professionals, also known as Experts. Experts compete and collaborate to answer those questions by leaving comments like this one.

Start your 30-day free trial to view this Expert Comment or ask the Experts your question.

 
[+][-]07/03/08 10:41 AM, ID: 21927588Assisted Solution

Assisted solutions are selected by the member who asked the question as a comment that contributed to their question's solution.

Start your 30-day free trial to view this Assisted Solution or ask the Experts your question.

 
[+][-]07/03/08 03:56 PM, ID: 21929996Author Comment

Often, when Experts are collaborating with members who have asked questions, they will request additional information about the problem. Askers respond with an author comment like this one.

Start your 30-day free trial to view this Author Comment or ask the Experts your question.

 
[+][-]07/04/08 02:23 AM, ID: 21931901Expert Comment

At Experts Exchange, members can ask their questions to thousands of technology professionals, also known as Experts. Experts compete and collaborate to answer those questions by leaving comments like this one.

Start your 30-day free trial to view this Expert Comment or ask the Experts your question.

 
[+][-]07/04/08 09:24 AM, ID: 21933859Author Comment

Often, when Experts are collaborating with members who have asked questions, they will request additional information about the problem. Askers respond with an author comment like this one.

Start your 30-day free trial to view this Author Comment or ask the Experts your question.

 
[+][-]07/04/08 09:55 AM, ID: 21933980Expert Comment

At Experts Exchange, members can ask their questions to thousands of technology professionals, also known as Experts. Experts compete and collaborate to answer those questions by leaving comments like this one.

Start your 30-day free trial to view this Expert Comment or ask the Experts your question.

 
[+][-]07/04/08 04:06 PM, ID: 21935189Author Comment

Often, when Experts are collaborating with members who have asked questions, they will request additional information about the problem. Askers respond with an author comment like this one.

Start your 30-day free trial to view this Author Comment or ask the Experts your question.

 
[+][-]07/06/08 06:27 PM, ID: 21942294Expert Comment

At Experts Exchange, members can ask their questions to thousands of technology professionals, also known as Experts. Experts compete and collaborate to answer those questions by leaving comments like this one.

Start your 30-day free trial to view this Expert Comment or ask the Experts your question.

 
[+][-]07/06/08 07:29 PM, ID: 21942481Author Comment

Often, when Experts are collaborating with members who have asked questions, they will request additional information about the problem. Askers respond with an author comment like this one.

Start your 30-day free trial to view this Author Comment or ask the Experts your question.

 
[+][-]07/06/08 08:16 PM, ID: 21942590Expert Comment

At Experts Exchange, members can ask their questions to thousands of technology professionals, also known as Experts. Experts compete and collaborate to answer those questions by leaving comments like this one.

Start your 30-day free trial to view this Expert Comment or ask the Experts your question.

 
[+][-]07/06/08 08:17 PM, ID: 21942594Administrative Comment

Experts Exchange has a courteous staff of administrators who help members get the most out of the website by means of administrative comments like this one.

Start your 30-day free trial to view this Administrative Comment or ask the Experts your question.

 
[+][-]07/19/08 10:42 PM, ID: 22044675Author Comment

Often, when Experts are collaborating with members who have asked questions, they will request additional information about the problem. Askers respond with an author comment like this one.

Start your 30-day free trial to view this Author Comment or ask the Experts your question.

 
 
Loading Advertisement...
20091021-EE-VQP-81 / EE_QW_Related_20080208