lazarus DBGrid lookup field (no creation)
lazarus / 16-Databases

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asimkon · 2020-06-11 16:35

I have been using Lazarus 2.x with Firebird 3 (via flamerobin) and i
have got two tables: appeals with a foreign key (promoter_id) and
promoter (id,fullname).

I would like to create a lookup field for DBGrid with field properties
from dataset appeals and lookup fields from dataset promoter.

Thus i have got the following script:

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
interface uses  Classes, SysUtils, Forms, Controls, Graphics, Dialogs,
DBGrids,Unit3,DB; type   { TForm5 }   TForm5 = class(TForm)   
DBGrid1: TDBGrid;    procedure FormShow(Sender: TObject);    procedure
showgrid;    procedure showlookup;  private   public   end; var 
Form5: TForm5; implementation {$R *.lfm} { TForm5 } procedure
TForm5.FormShow(Sender:
TObject);begin //showlookup; showgrid; showlookup;end; procedure TForm
5.showgrid;begin  appeals.SQLQuery2.Close; appeals.SQLQuery2.SQL.Text:
='select * from appeals where datediff(day,cast(''Now'' as
date),cast(date_judgement as date))<5 and date_court IS NOT NULL';  ap
peals.DBConnection.Connected:=True; appeals.SQLTransaction1.Active:=Tr
ue; //appeals.SQLQuery2.Open;  //appeals.DataSource1.DataSet:=appeals.
SQLQuery2; //DBGrid1.DataSource:=appeals.DataSource1;  DBGrid1.Columns
.Items[1].Width:=120; DBGrid1.Columns.Items[0].Visible:=false; DBGrid1
.Columns.Items[1].Title.Caption:='Name'; DBGrid1.Columns.Items[2].Titl
e.Caption:='Date Entry'; DBGrid1.Columns.Items[3].Title.Caption:='Date
Suspension'; DBGrid1.Columns.Items[4].Title.Caption:='Date
Examination'; DBGrid1.Columns.Items[5].Title.Caption:='Date Final'; DB
Grid1.Columns.Items[6].Title.Caption:='Promoter'; end; procedure TForm
5.showlookup;begin  appeals.SQLQuery4.Close; appeals.SQLQuery4.SQL.Tex
t:='select id,fullname from promoter'; //appeals.SQLQuery4.Open;  DBGr
id1.Columns.Items[6].Field.FieldName:='promoter_id'; DBGrid1.Columns.I
tems[6].Field.FieldKind:=fkLookup; DBGrid1.Columns.Items[6].Field.KeyF
ields:='promoter_id'; DBGrid1.Columns.Items[6].Field.LookupDataSet:= a
ppeals.SQLQuery4; DBGrid1.Columns.Items[6].Field.LookupKeyFields:='id'
; DBGrid1.Columns.Items[6].Field.LookupResultField:='fullname'; DBGrid
1.Columns.Items[6].Field.DataSet:=appeals.SQLQuery2;  appeals.SQLQuery
4.Open; appeals.SQLQuery2.Open;  appeals.DataSource1.DataSet:=appeals.
SQLQuery2; DBGrid1.DataSource:=appeals.DataSource1;end; end.         
                                                                     
            
As soon as i run it, i receive the following error (attached) or in
text description ElistError:ListIndex (1) out of bounds.

Additionally I have played with my code by running and opening first
the queries but no lookupfield is shown in Promoter column grid (only
numbers and no text description). Unfortunately there is no
bibliography or code examples of creating lookup fields or computed in
Lazarus IDE.

Any help would be convenient to me!

Regards