ORM and preventing memory leaks

[mrluigi2017]

Hi,

In my application I have the following code:

Requirement := TPMRequirement.Create;
try

Requirement.PMItem := Orm.FromDataset<TPMItem>(FItemTable, True, True);
Requirement.RequirementItem := Orm.FromDataset<TPMRequirementItem>(FDetailTable, True, True);

…

Because the constructor of the TPMRequirement instanciates both PMItem and RequirementItem the PMItem and RequirementItem should be freed before getting the value from the ORM else you will have a memory leak. To accomplish this I have added the following code:

procedure TPMRequirement.SetPMItem(const Value: TPMItem);
begin
FPMItem.Free;
FPMItem := Value;
end;

After adding this code I got a Invalid Pointer Exception but I don’t understand why. I have tested similar code without kbmmw/orm and it just works fine. If I free the both items before the ORM code is called it works fine, but that solution is a bit uggly.

Any suggestions/best practice?

 

[kimbomadsen]

Well… one thing might be that the initial free is running on a bad pointer.
But it would be helpful to see how the definition of TPMItem and TPMRequirementItem actually is.

/Kim

[Author]

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