SQLDB - something else than TBookmark?
lazarus / 16-Databases

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Dibo · 2012-12-28 13:29

Hi,

TDataset has bookmarks, but I must navigate to this bookmark when I
want read value from row. Can I somehow remember pointers to custom
rows and read it fields without gotobookmark? I temporary solved this
by copy all field values to my record type.

Regards

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marcov · 2012-12-28 15:56

Quote from: Dibo on December 28, 2012, 02:29:39 pm
TDataset has bookmarks, but I must navigate to this bookmark when I
want read value from row. Can I somehow remember pointers to custom
rows and read it fields without gotobookmark? I temporary solved this
by copy all field values to my record type.


Afaik no. TDataset is basically a window on the result set, and not
all items of the result set might be in memory, only a limited size
buffer.

Any operation that changes the current record might reload/reallocate
the buffer, thus invalidating all pointers.
The gotobookmark makes sure the correct buffer is loaded.

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Dibo · 2012-12-28 16:13

Thanks marcov for explanation

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Dibo · 2012-12-28 17:27

Oh, quick question about TBookmark. Should I remember about
FreeBookmark? Because wiki say nothing in bookmark example. When
should I free it?