DBLookupCombobox can not convert null to int64 for data submission
lazarus / 16-Databases

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asimkon · 2020-06-10 08:03

I have been using Lazarus 2.x with Firebird 3 (via flamerobin) and i
try to commit records into a table with a foreign key via
TSQLConnection, TSQLQuery, TDataSource (data module).

I run the following script successfully in order to configure
initially DBLookupCombobox (reference table) and the records are
displayed without any problem from table1.

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
TForm3.FormCreate(Sender: TObject);  begin  appeals.SQLQuery4.Close; 
appeals.SQLQuery4.SQL.Text:='select id,fullname from promoter';  
appeals.SQLQuery4.Open;  
appeals.DataSource2.DataSet:=appeals.SQLQuery4; 
DBLookupComboBox1.ListSource:=appeals.DataSource2; 
DBLookupComboBox1.ScrollListDataset:=True; 
DBLookupComboBox1.Style:=csDropDownList; 
DBLookupComboBox1.KeyField:='id';  DBLookupComboBox1.DataField:='id'; 
DBLookupComboBox1.ListField:='fullname';       end; 
Afterwards i use the following script to submit all selected data to
table2 with foreign key

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
TForm3.Button1Click(Sender: TObject);begin  
appeals.SQLTransaction1.Active:=false;  
appeals.SQLQuery1.SQL.Text:='UPDATE appeals set
name=:name,date_entry=:entry,date_suspended=:suspended,'+ 
'date_court=:court,date_judgement=:judgement,promoter_id=:code where
id='+IntToStr(row_num);   appeals.SQLQuery1.Params.ParamByName('name')
.AsString:=Trim(Edit1.Text);  appeals.SQLQuery1.Params.ParamByName('en
try').AsDate:=DateTimePicker1.Date;  appeals.SQLQuery1.Params.ParamByN
ame('suspended').AsDate:=IncDay(DateTimePicker1.Date,10);  appeals.SQL
Query1.Params.ParamByName('court').AsDate:=DateTimePicker2.Date;  appe
als.SQLQuery1.Params.ParamByName('judgement').AsDate:=IncDay(DateTimeP
icker2.Date,20);  appeals.SQLQuery1.Params.ParamByName('code').AsInteg
er:=DBLookupComboBox1.KeyValue;  
appeals.SQLTransaction1.StartTransaction;  appeals.SQLQuery1.ExecSQL; 
appeals.SQLTransaction1.Commit;  Application.MessageBox('Record
submission with success !', 'Information', MB_ICONINFORMATION);      
                         end;
Unfortunately i receive the following error ( attached as image) that
has to do with
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 appeals.SQL
Query1.Params.ParamByName('code').AsInteger:=DBLookupComboBox1.KeyValu
e;
I try to submit data via edit, datetimepicker and DBLookupCombobox as
foreign key to a table (attached as image).

Any help would be convenient to me!

Regards

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rvk · 2020-06-10 10:16

At the top of the buttonclick you close the transaction of
appeals.SQLQuery4. This will effectively close the dataset.
Because DBLookupComboBox1 is connected to that dataset (via
ListSource), you also set the Keyvalue of DBLookupComboBox1 to null.

After that you try to assign a null to a asInteger (which isn't
possible because null isn't a number).

I'm not sure what you are trying to do with the DBLookupComboBox but
you could first save the code (or  DBLookupComboBox1.KeyValue) before
closing the transaction. Then you can assign that saved value to
asInteger.

But as I see it in the code... you don't want your code field to
change, do you?
You UPDATE a record and want to assign 'code' field with the same
value as the DBLookComboBox (which has the previous valie). So why
don't you just remove de code assignment in the UPDATE statement ??