I have a small database I'm using dbgo, I have a DBgrid displaying my records, I need to know how to delete a record and refresh the database where the index arrow stays in the same position or at least go to the next? but currently my index arrow jump to start form the beginning each time I refresh !
Just keep and reset Recno
var
I:Integer;
.......
I := Ads.Recno;
Ads.Delete;
Ads.Recno := I;
an example implementation for usage with DBNavigator could be
Procedure DeleteAndKeepRecno(Ads: TCustomAdoDataset);
var
rn: Integer;
begin
rn := Ads.RecNo;
Ads.Delete;
Ads.RecNo := rn;
end;
procedure TForm4.DBNavigator1Click(Sender: TObject; Button: TNavigateBtn);
begin
if Button = nbDelete then
begin
DeleteAndKeepRecno (TCustomAdoDataset(TDBNavigator(Sender).DataSource.DataSet));
Abort;
end;
end;
Related
I have two tables TEST_DEPT and TEST_DEPT$AUDIT in Oracle 11g.
I have made an insert update delete after trigger. However, the last column in the Audit table is called REASON. The idea is after making the update for example, Oracle to prompt the user to fill in the REASON column.
This is what the after trigger looks like:
CREATE OR REPLACE TRIGGER auditDEPTAR AFTER
INSERT OR UPDATE OR DELETE ON TEST_DEPT FOR EACH ROW
DECLARE
test TEST_DEPT$audit%ROWTYPE;
BEGIN
IF inserting THEN test.change_type := 'INSERT';
ELSIF updating THEN test.change_type := 'UPDATE';
ELSE test.change_type := 'DELETE';
END IF;
test.changed_by := user;
test.changed_time := sysdate;
CASE test.change_type
WHEN 'INSERT' THEN
test.DEPTNO := :new.DEPTNO;
test.DNAME := :new.DNAME;
test.LOC := :new.LOC;
ELSE
test.DEPTNO := :old.DEPTNO;
test.DNAME := :old.DNAME;
test.LOC := :old.LOC;
END CASE;
INSERT INTO TEST_DEPT$audit VALUES test;
END;
Can it be done or should I use function or something else for workaround?
Please, help!
I am using the ado connection a adoquery and dsr and adotable
I have a database with bookingnumbers as a field in the table client.
I would like to get the last bookingnumber in the field and store it in a variable.
The booking number is saved as text on access.
So far I have:
Var
sNum : string;
....
sNum := Datamodule1.tblClient['BookingNumber'].Last;
but it is not working.
please help?
It is not a good idea to try and find the maximum value of a field by navigating the dataset, especially if the dataset isn't necessarily ordered by the field in question. Try something like this instead:
function TForm1.GetMaxBookingNumber : Integer;
var
Q : TAdoQuery;
begin
Q := TAdoQuery.Create(Nil);
Q.Connection := DataModule1.AdoConnection1; // or whatever the name of your connection is
try
Q.SQL.Text := 'SELECT MAX(BookingNumber) FROM CLIENT';
Q.Open;
// the `not IsNull` in the following allows for the table being empty
if not Q.Fields[0].IsNull then
Result := Q.Fields[0].AsInteger
else
Result := -1;
finally
Q.Free;
end;
end;
So here is what i wanted :
var
sNum : string;
procedure button click
begin
with Datamodule1 do
begin
qryClient.SQL.Add('SELECT BookingNumber FROM Client');
qryClient.Open;
qryClient.last;
sNum := qryClient['BookingNumber'];
end;
end;
The TListBox called lboMtrlList is populated with records from the database. The data displays properly when I run the application. When I click on any item in the list, shows the error:
Index out of range (-1)
despite the list not being empty.
Here's the code for populating the lboMtrlList:
procedure TfrmMakeQuote.FormCreate(Sender: TObject);
begin
con := TFDConnection.Create(nil);
query := TFDQuery.Create(con);
con.LoginPrompt := false;
con.Open('DriverID=SQLite;Database=C:\Users\katiee\Documents\Embarcadero\Studio\Projects\ProgramDatabase;');
query.Connection := con;
performQuery;
query.SQL.Text :=
'SELECT [Material Description] FROM MtrlDatabase ORDER BY MtrlID';
try
query.Open;
lboMtrlList.Items.Clear;
while not query.EOF do
begin
lboMtrlList.Items.Add(query.Fields[0].AsString);
query.Next;
end;
finally
query.Close;
end;
//ledtDesc.Height := 81;
//ledtNotes.Height := 51;
end;
I want to be able to double click on an item in the lboMtrlList and move it to another TListBox called lboSelectedMtrl. Here's the code:
procedure TfrmMakeQuote.lboMtrlListDblClick(Sender: TObject);
begin
lboMtrlList.Items.Add(lboSelectedMtrl.Items.Strings[lboSelectedMtrl.ItemIndex]);
end;
I want to be able to double click on an item in the lboMtrlList and move it to another TListBox called lboSelectedMtrl.
Your code is doing the opposite of that. It is trying to move an item from lboSelectedMtrl to lboMtrlList. You are getting the bounds error because there is no item selected in lboSelectedMtrl (lboSelectedMtrl.ItemIndex is -1).
Swap the ListBox variables, and add some error checking:
procedure TfrmMakeQuote.lboMtrlListDblClick(Sender: TObject);
var
Idx: Integer;
begin
Idx := lboMtrlList.ItemIndex;
if Idx <> -1 then
lboSelectedMtrl.Items.Add(lboMtrlList.Items.Strings[Idx]);
end;
I'm having yet another problem with Delphi. I wrote a piece of code that should check if a field in a database table equals to 0, and if that is true, changes font color and caption of a certain button. It runs on creation of the main form. However, when I run the program, nothing happens - the program does not appear and I get no errors. I seriously don't know what's wrong, seems like some kind of an infinite loop.
Here's the code:
procedure TForm1.FormCreate(Sender: TObject);
begin
ADOTableStorage.First;
while not ADOTableStorage.Eof do
If ADOTableStorage.FieldByName('amount').AsInteger = 0 then
begin
btStorage.Font.Color := clRed;
btStorage.Caption := 'Some items are out of stock!';
Break;
end;
ADOTableStorage.Next;
end;
Note: The ADOTableStorage table is a on the detail table in a Master-Detail connection.
Thanks!
I guess you are missing a begin/end in the while loop. Try this.
procedure TForm1.FormCreate(Sender: TObject);
begin
ADOTableStorage.First;
while not ADOTableStorage.Eof do
begin
If ADOTableStorage.FieldByName('amount').AsInteger = 0 then
begin
btStorage.Font.Color := clRed;
btStorage.Caption := 'Some items are out of stock!';
Break;
end;
ADOTableStorage.Next;
end;
end;
Using Delphi Steema TeeChart component, if I link a BarSeries to a dataset using the user interface, it shows up fine, but if I do it using code (which I need to), it's only showing one bar, even when I have several records in the database. What am I doing wrong?
Code:
var
i:Integer;
Bar:TBarSeries;
begin
ADataSet.Close;
ADataSet.LoadFromDataSet(mtbl);
ADataSet.Active := true;
ADataSet.First;
ASource.DataSet := ADataSet;
Bar := TBarSeries.Create(AChart);
Bar.Assign(Series2);
Bar.ParentChart := AChart;
Bar.DataSource := ASource;
Bar.XLabelsSource := 'Date';
Bar.YValues.ValueSource := 'Load';
for i := 0 to AChart.SeriesCount - 1 do
begin
AChart.Series[i].CheckDataSource;
end;
ADataSet is a DevExpress MemData (TdxMemData). When I run the program, the X axis is only showing one bar, the first record in the dataset, even though I have 4 records in the dataset.
This code works for me (using an Access database with fields ID and Height, I dropped a TDBChart, TADODataSet, and a TButton on a form):
procedure TForm1.Button1Click(Sender: TObject);
var
Bar : TBarSeries;
begin
ADODataSet1.Close;
ADODataSet1.ConnectionString := 'Provider=Microsoft.Jet.OLEDB.4.0;...';
Bar := TBarSeries.Create(DBChart1);
DBChart1.AddSeries(Bar);
Bar.ParentChart := DBChart1;
Bar.DataSource := ADODataSet1;
Bar.XLabelsSource := 'ID';
Bar.YValues.ValueSource := 'Height';
ADODataSet1.Active := true;
end;
Note that the Datasource should be a TTable, TQuery, or TDataSet (not a TDataSource - go figure!).
Hope this helps.
TChart refreshes the query each time you set
ADataSet.Active := true;
so, move this command to the end of your block (e.g. after you've set up the series properties).