DBGrid multiselect
lazarus / 16-Databases

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teresa · 2024-05-18 09:24

I have a DBGrid, with multi-select enabled.

I need to know which rows are selected, and short of checking the
entire grid row  by row have come up short. With more than 2000 rows,
that is time consuming

Is there a more direct way? I see there is the bookmark list, but
haven't had any success with it.

Thanks
Teresa

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jesusr · 2024-05-18 18:12

You could use Bookmarklist's enumerator, something like:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i         for
book in theDbGrid.SelectedRows.GetEnumerator([]) do begin          <do
something with the current record>        end; 
GetEnumerator takes a set of options:
breDisableDataset. Which disables any db gui control, so iterating
over selected records is fasterbreStopOnInvalidBookmark. Which stops
iteration if a bookmark is invalidbreRestoreCurrent. Which restores
the current record after iterating selected records has finished

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teresa · 2024-05-19 02:36

Thanks Jesusr.

I've had no success so far interpreting the byte array (15 bytes)
returned for each bookmark.

Is there any documentation on that?

T.

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teresa · 2024-05-19 05:02

Ah, solved. A post from 2017 by GAN showed me how to use the bookmark,
and relate it to the dataset.

Thanks all
T.

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CharlyTango · 2024-05-19 08:54

Could you please post the link, so this thread is linked to the
solution ?

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TRon · 2024-05-19 11:09

Quote from: CharlyTango on May 19, 2024, 10:54:33 amCould you please
post the link, so this thread is linked to the solution ?
The only related post from GAN that I was able to locate can be found
in this thread

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teresa · 2024-05-19 22:01

Quote from: CharlyTango on May 19, 2024, 10:54:33 amCould you please
post the link, so this thread is linked to the solution ?

Sure:

https://forum.lazarus.freepascal.org/index.php/topic,36900.msg246513.h
tml#msg246513

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egsuh · 2024-05-22 03:32

I'm trying to extend this to delete multiple rows at once in following
way. BeforeDelete event is to delete the record from SQL server before
the record is deleted at the TDataSet.

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
TSampleList.DBNavigator1Click(Sender: TObject;   Button:
TDBNavButtonType);var   i: Integer;begin   if Button = nbDelete then
begin      for i:=0 to dbgSampleList.SelectedRows.Count-1 do       
 with dbgSampleList.DataSource.DataSet do         begin           
GotoBookmark(pointer(dbgSampleList.SelectedRows.Items[i]));          
Delete;         end;   end;end; procedure
TSampleList.bdsSampleListBeforeDelete(DataSet: TDataSet);var 
 tclause: string;begin   TClause := Format('project_id=''%s'' and
respondent_id=%d',             [pid,
bdsSampleList.FieldByName('RID').AsInteger]);   if not
DataAccess.DeleteARecord('SampleList', tclause)      then
bdsSampleList.Cancel;end; 
This deletes as I want, but it causes memory leak, as attached in the
image. What might have caused this?