Solved

Delphi 7 : Lookup Field?

Posted on 2007-11-19
17
1,098 Views
Last Modified: 2013-11-23
Hi Experts,

I have an TDBGrid and would like the use to be able to pick from a dropdown in the list.
For example:

Table1:
ColorID INT PK
ColorCode VARCHAR(10)
Description VARCHAR(100)

Table2:
VehicleID INT PK
ColorID INT
RegNumber VARCHAR(20)


When inserting a new row in the DBGrid for Table2, I would like to user to be able to select from dropdown in grid from all the available colorcodes and after selecting the ColorID should be saved in this table.

I managed to get what I am looking by means of creating a new lookup field on my ADOTable Component for Table2. But when inserting a new row I receive the following error:

"raised exception class EOleException with message 'An unkown error has occurred.' Process stopped...."

Please advise.
0
Comment
Question by:Marius0188
17 Comments
 
LVL 21

Assisted Solution

by:developmentguru
developmentguru earned 150 total points
ID: 20312096
We would need to see your code for starters.  There is nothing wrong with how you are handling the lookup field, that in itself should not cause an error.  I suspect that something was missing in how it was set up.  Can you show us a simplified example?
0
 

Author Comment

by:Marius0188
ID: 20312820
Here is a screenshot of my setup:
http://www.medalware.com/delphi_lookup.JPG

I use a normal TDBGrid and TADOTable components.

Thanks!
0
 
LVL 18

Assisted Solution

by:Johnjces
Johnjces earned 150 total points
ID: 20315434
I am confuised, but that is pretty normal for me...

Are you storing in your dataset the color as a string name such as clRed, or clBlack or are you storing the actual color identifier, which will be a hex value such as $000000FF, (decimal 255 which is clRed) .

ColorID as an Int sounds OK if you are storing the color value, but I do not know about what you are storing in ColorCode and if that is like clRed.

Not sure if it is a table/database issue or some other code part failing when getting the color.

A code snippet or two will really be helpful as developmentguru has suggested. A picture can be worth a thousand words, but...

John
0
 

Author Comment

by:Marius0188
ID: 20319069
I have build a demo app using Firebird database and Interbase components.
I have created a lookup table exactly as I have done with the ADO table components and it is WORKING here.

I guess there is something else about the TADOTable component.
Let me see if I can provide you with a demo.


Cheers
0
 

Author Comment

by:Marius0188
ID: 20319183
Ok I have produced a demo for you:
http://www.medalware.com/demo_lookup.zip

Just connect both TIBDatabase & TADOConnection components to the databasis that is in a subfolder.
1 x Firebird DB
1 x MS SQL MDF DB

The firebird is working 100%.
The SQL db is giving me that nasty exception.


Thanks in advance!

0
 

Author Comment

by:Marius0188
ID: 20319221
It looks like a bug in ADO.
http://qc.codegear.com/wc/qcmain.aspx?d=46248

Is there any work arounds?
Where can I get the latest Delphi 7 updates?


Thanks!
0
 

Author Comment

by:Marius0188
ID: 20319310
Can one connect to SQL 2005 db without using ADO components?
Is there any other good alternative components or methods one can try?
0
 
LVL 8

Accepted Solution

by:
RickJ earned 200 total points
ID: 20331714
Hello marius0188,
I downloaded and tried your example and it works fine for me.
Guessing it may be something that was fixed with the delphi 7 service update 1. Do you have that installed?
I think you need to be a registered user to download it.

Rick.
0
Threat Intelligence Starter Resources

Integrating threat intelligence can be challenging, and not all companies are ready. These resources can help you build awareness and prepare for defense.

 

Author Comment

by:Marius0188
ID: 20332773
Yes I do have that update.
But if I remember correctly, when installing that update it prompt to notify me about missing files where after I just clicked ignore. Maybe it has something to do with that.

Mmmmh, I wonder if I can just update the ADO dcu's etc by getting them from you.
Will that not work?
0
 
LVL 8

Expert Comment

by:RickJ
ID: 20333275
Much cleaner to get your intall to work correctly, but worth a shot I guess.
Would back up before attempting.
Here you go.
http://www.logancontracting.com.au/ado/ado.zip
0
 

Author Comment

by:Marius0188
ID: 20333516
Nope, still not working.

Are you also using Delphi 7 Enterprise?
0
 
LVL 8

Expert Comment

by:RickJ
ID: 20333530
Delphi 7 pro. I would have thought the ado stuff would have been the same. But I could be wrong.
Not sure how else I can help you...
0
 

Author Comment

by:Marius0188
ID: 20333790
You don't think it might be the TDBGrid component?
Maybe you must sent me your source and let me try that.

0
 
LVL 8

Expert Comment

by:RickJ
ID: 20336974
I still think getting your install correct would be a better way to go. But again,
Here you go.
http://www.logancontracting.com.au/ado/dbgrids.zip
0
 

Author Comment

by:Marius0188
ID: 20337406
Yip, after this one I will go for re-install and then apply that 7.1 update.
But need a quick fix because installing all my components from start takes 1-2 days.

Enjoy
0
 

Author Comment

by:Marius0188
ID: 20337417
Ok but another thing is:
It is only in the compiler (IDE) that I get the exception EOleException.

When running outside the IDE no problem.
Should I still be worried?
0
 

Author Comment

by:Marius0188
ID: 20372089
Ok I will accept that this might be an installation problem.
Have not tested yet but will try to re-install as soon as I have time available.

Lets split the points....

Thanks to all!
0

Featured Post

How to run any project with ease

Manage projects of all sizes how you want. Great for personal to-do lists, project milestones, team priorities and launch plans.
- Combine task lists, docs, spreadsheets, and chat in one
- View and edit from mobile/offline
- Cut down on emails

Join & Write a Comment

Suggested Solutions

Title # Comments Views Activity
Delphi XE7 Rest Client 2 176
Delphi TcxGrid group footer summary 3 146
Help on project with Soap 10 43
find a node in VST 2 47
The uses clause is one of those things that just tends to grow and grow. Most of the time this is in the main form, as it's from this form that all others are called. If you have a big application (including many forms), the uses clause in the in…
Have you ever had your Delphi form/application just hanging while waiting for data to load? This is the article to read if you want to learn some things about adding threads for data loading in the background. First, I'll setup a general applica…
Internet Business Fax to Email Made Easy - With eFax Corporate (http://www.enterprise.efax.com), you'll receive a dedicated online fax number, which is used the same way as a typical analog fax number. You'll receive secure faxes in your email, fr…
Illustrator's Shape Builder tool will let you combine shapes visually and interactively. This video shows the Mac version, but the tool works the same way in Windows. To follow along with this video, you can draw your own shapes or download the file…

758 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

18 Experts available now in Live!

Get 1:1 Help Now