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Jacek Laskowski

FireDAC and AV in TFDDatSView.RemRef()

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Posted (edited)

I have a strange problem with FireDAC (Delphi 10.3.2)


I create TFDMemTable dynamically, then I create its structure and index on base key (by memTable.Indexes.Add()).
Next, I import data from JSON file (saved previously by TFDQuery object):

 

memTable.LoadFromStream(x, sfJSON);

 

AV is raised in this FD code:

 

procedure TFDDatSView.RemRef;
begin
  FRefs.RemRef;
end;

And on this import I get access violation in FireDAC code, because internal TFDDatSView field is nil (see attached screenshot)!

 

When I remove the creation of the index there is no error. But I can't do it, because it's part of a big, generic mechanism and it's needed.

 

The index is created when MemTable is in dsInactive mode, can it be the cause?

I also noticed that when I do Open/Close this MemTable, there is no error either.


What is the cause and how to avoid it without performing spells (like close/open)?

 

vps_2020.03.12_02.png

Edited by Jacek Laskowski

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OK, the problem is not in FireDAC, but in the code associated with Spring4D.

Injected interface for reasons I don't know yet reduces the reference counter to zero and is released, and with it FD objects.

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