[Lazarus] GDB crash when I try to debug

[Pierre Delore]

Hello Joost and Michael,

Sorry for the late post.

The problem is that fieldsdef and fields don´t get syncronized.

You asked about the TClientDataset behavior. Honestly i use only the fields 
editor to manage the fields. I add then through fields editor where is 
possible to define fields types: Data,Calculated,Lookup,Internalcalc and 
Aggregate. Of course that the last two are specific to ClientDataset.
Then I just click in Create DataSet and all is ok. Fieldsdef reflects the 
same fields i added through fields editor.

I tested the other way, just to see if there was something different. I used 
fieldsdef editor, than created dataset and than all fields could be added 
with fields editor.

Bellow, the steps to reproduce:

Through FieldsDef:
- Create new fields through FieldsDef property editor;
- Than call Create Dataset;
- Through Fields property Editor, Added all fields (CTRL+A)

Through Fields Editor:
- Insert new fields of any type supported (Data,Calculated,Lookup);
- Than call Create DataSet;
- All fields are auto inserted in fieldsdef property.

This behaviour do not occur with the components in Lazarus Data Access 
pallete.

BTW, i created screenshots of the problem within Lazarus. If you want, i can 
send you.


Other problem i´ve noticed is the limited use of Lazarus NewField form. It 
is not Delphi compatible, based in what we discussed so far. It does not 
permit insert fields o type Data, as you noticed in your previous post. This 
could be a problem to users migrating from Delphi.

And one last note is about the Lazarus behaviour when adding available 
fields. The dialog that appears to let you select the fields, do not work 
with multiselect. I tried to select all fields to add at once, and it simply 
gives an error. If i select one by one, it works.

If you have any question, feel free to ask. I have a demo copy of D7 here, 
and i can test whatever you want.

Thanks in advance.


Marcelo



Michael Van Canneyt michael at freepascal.org
Wed Jul 14 17:01:45 CEST 2010


On Wed, 14 Jul 2010, Joost van der Sluis wrote:

> On Tue, 2010-07-13 at 12:23 -0300, Marcelo B de Paula wrote:
>> Thanks Joost for the answer.
>>
>> I forgot to mention that i am using Lazarus trunk (0.9.29 rev 26602) with
>> fpc 2.5.1.
>
> A perfect example that this information is necessary. Now I wrote a
> complete mail with useless information. (My last email that is)
>
>> I just mentioned TClientDataset because of others said here in the list 
>> and
>> in Lazarus forum.
>>
>> My concern is that the component seems to be incomplete e can cause some
>> user headache and needs to be bug reported.
>>
>> If it is available in component palette, IMHO, it could offer more in 
>> design
>> time, and not assume
>> that the final user will know that he must do all the stuff in code.
>>
>> BTW, if someone has some sample of its use, please send it to me.
>> Thanks in advance.
>
> There are a lot in packages/fcl-db/tests. But maybe not very 'easy' to
> understand.
>
> I now remember a bur-report that looks like your story. Someone tried to
> create a dataset using the fields definitions. But that is, afaik, not
> possible. Also not with a TCLientDataset. (If this is possible using a
> TClientDataset, please tell me. In that case I have some coding to do)

If you mean fill up FieldDefs, and call 'CreateDataset' : Yes, you can.
You can even do it with Persistent fields present.

Michael.