asked on

Adding a Lookup Field to a ADODataset in runtime?

Hi,
I like to add a LookupField to a ADO Dataset at runtime, since there's always a
different query filling the dataset I don't know the fields in design time.
But I do know the one field I want to use to get filled with data from the
lookupfield is always there.
The the LookupField needs to be connected to another dataset for the lookupdata.
What need I do to create this kind of field after the ADODataset opens?

Regards,
Corpa

olmy

Hi

I found it difficult also to add persistent fields at runtime, but after searching I find it quite easy to do.
I don't have Delphi at this computer, but the basic manover is something like this.

1. create persistent fields for every field in a database. Do this just before calling the <query>.open-procedure.
- I did a simple routine that checkes fieldtypes from query's "fielddefs" (or "fields") that can be retrieved before calling open-procedure. It creates TStringField, TIntegerField, TMemoField, etc. depending the actual field type.
- you have to create persistent field for every field you wish to use with your query.
- dataset-property must be also defined

2. also create new persistent field for the lookupfield
3. open the database ;)

I'll send you more detailed examples tommorrow when I have Delphi at my reach.

Regards
Olmy

ASKER CERTIFIED SOLUTION

olmy

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

corpa

ASKER

This is exactly what I wanted,
many thanks,

corpa

rfwoolf

Olmy thanks so much for the fantastic solution. I'm posting this 5 years later and it's been a great deal of help! :)

olmy

I'm very happy that you found what you were looking for. Thank you for your lovely message :D
Olmy