Delphi how to save 3 datasources with one save button? - delphi

I got a problem with saving all values from 3 datasources into a SMDBGrid with another datasouce.
I got AdressID, ContactpersonID and RelationID.
Those all dont match each others.
The problem is that my SMDBGrid has another datasource then those 3.
I wanna save them with one button.
Tried many ways but can't find a good result.
this is the code i use right now for my Insert button:
procedure TFRelatiebeheer.ToolButton1Click(Sender: TObject);
begin
DRelatiebeheer.ContactpersonID.Insert;
DRelatiebeheer.RelationID.Insert;
DRelatiebeheer.AdressID.Insert;
end;
This is the code i use for my save button right now
if (DRelatiebeheer.ContactpersonID.State in dsEditModes) then
if not (DRelatiebeheer.ContactpersonID.State in [dsInsert]) then
begin
KJSMDBGrid1.RefreshData;
KJPanel4.Visible := True;
end
else
begin
if (DRelatiebeheer.ContactpersonID.State IN dsEditModes) then
DRelatiebeheer.ContactpersonID.Post;
if (DRelatiebeheer.AdressID.State IN dsEditModes) then
DRelatiebeheer.AdressID.Post;
end;
Hope you have a good sight for what I am doing right now, if not please notify.
I got the problem with the datasources that need to be saved on 1 click and then be refreshed in the database and in the Grid.
That means that when I insert a Contactperson there needs to be a AdressID and a RelationID coupled with it.
After that the grid needs to reload all of the data.

Focusing on the given problem
Depending on the intended behavior (should it be possible posting only one or two table(s) or is it necessary to post all tables) the first thing to do would be to ensure that the tables can be posted. You coulds create a function for each table e.g. CanAdressIDBePosted:Boolean to check if required fields are already entered. The condition of the table ContactpersonID would contain additional conditions: needed fields are entered AND CanAdressIDBePosted AND CanRelationIDBePosted. You could create an Action which would be bound on your button with an OnUpdate event which could look like this:
procedure TForm1.PostActionUpdate(Sender: TObject);
begin
TAction(Sender).Enabled := CanAdressIDBePosted and CanContactpersonIDBePosted and CanRelationIDBePosted;
// depending on your requirements (e.g. no need to post RelationID if not entered) it also could be
TAction(Sender).Enabled := CanAdressIDBePosted or CanContactpersonIDBePosted ;
end;
procedure TForm1.PostActionExecute(Sender: TObject);
begin
if CanAdressIDBePosted then AdressID.Post; // ensure ID fields will be generated
if CanRelationIDBePosted then RelationID.Post; // ensure ID fields will be generated
if CanContactpersonIDBePosted then
begin
ContactpersonID.FieldByName('AdressID').value := AdressID.FieldByName('ID').Value;
ContactpersonID.FieldByName('RelationID').value := RelationID.FieldByName('ID').Value;
end;
DateSetBoundToTheGrid.Requery;
// furthor actions you need
end;
Function TForm1.CanAdressIDBePosted:Boolean;
begin
// example implementation
Result := (AdressID.State in [dsEdit,dsInsert]) and (not AdressID.FieldByName('NeededField').IsNull);
end;
Function TForm1.CanContactpersonIDBePosted:Boolean;
begin
// example implementation
Result := (ContactpersonID.State in [dsEdit,dsInsert]) and (not ContactpersonID.FieldByName('NeededField').IsNull)
and CanAdressIDBePosted and CanRelationIDBePosted;
end;
An addidtional Action should be created to cancel if needed:
procedure TForm1.CancelActionExecute(Sender: TObject);
begin
AdressID.Cancel;
RelationID.Cancel;
ContactpersonID.Cancel;
end;
procedure TForm1.CancelActionUpdate(Sender: TObject);
begin
TAction(Sender).Enabled := (AdressID.State in [dsEdit,dsInsert])
or (RelationID.State in [dsEdit,dsInsert])
or (ContactpersonID.State in [dsEdit,dsInsert]);
end;
In general I am not sure if the approach you took ist the best which can be taken, since from the structure given IMHO it should be possible to assign already existing relations and adresses to new generated contactpersons, but that would be another question.

This code just looks somewhat random to me. What SHOULD happen there ?
if (DRelatiebeheer.ContactpersonID.State in dsEditModes) then
// remember this check (1)
if not (DRelatiebeheer.ContactpersonID.State in [dsInsert]) then
// this check better written as "...State = dsInsert"
begin
// why don't you call DRelatiebeheer.ContactpersonID.Post to save chanegs ?
KJSMDBGrid1.RefreshData;
KJPanel4.Visible := True;
end
else
begin
if (DRelatiebeheer.ContactpersonID.State IN dsEditModes) then
// you already checked this above (1), why check again ?
DRelatiebeheer.ContactpersonID.Post;
if (DRelatiebeheer.AdressID.State IN dsEditModes) then
DRelatiebeheer.AdressID.Post;
end;
// so what about DRelatiebeheer.RelationID ?
For what i may deduce, you don't have to make any complex if-ladders, you just have to literally translate your words to Delphi. You want to save three tables and then refresh the grid. Then just do it.
procedure TFRelatiebeheer.SaveButtonClick(Sender: TObject);
begin
DRelatiebeheer.ContactpersonID.Post;
DRelatiebeheer.RelationID.Post;
DRelatiebeheer.AdressID.Post;
DatabaseConnection.CommitTrans;
KJSMDBGrid1.RefreshData;
KJPanel4.Visible := True;
end;
Just like you was told in your other questions.
Delphi save all values from different datasources with 1 save button
Delphi set Panel visible after post
PS. ToolButton1Click - plase, DO rename the buttons. Believe me when you have 10 buttons named Button1, Button2, ...Button10 you would never be sure what each button should do and would mix everything and make all possible program logic errors.

Related

Delphi 10.4 - Sort Memtable by clicking Stringgrid Header

I feel like an idiot because my question seams so simple but I don't get it done :D
My Settings is that:
One Dataset (Memtable), One Stringgrid. The Grid is bind via live Bindungs.
I would like to sort my Columns by clicking on the GridHeader. In the OnHeaderClick Event I get an tColumn Object. I only can read the Column.Header String, but I changed the Text from the Header to a more speakable Text. When I put Column.header into Memtable.Indexfieldsname Memtable says that field does not exist, what is right, but I don't know how to get the right Fieldname from the column.
What you want is quite straightforward to do. In the example below, which uses the demo data from
the Biolife demo, I've linked the StringgRid to the FDMemTable entirely by binding objects
created in code so that there is no doubt about any of the binding steps or binding properties,
nor the method used to establish the bindings.
procedure TForm2.FormCreate(Sender: TObject);
var
BindSourceDB1 : TBindSourceDB;
LinkGridToDataSourceBindSourceDB1 : TLinkGridToDataSource;
begin
// Note : You need to load FDMemTable1 at design time from the sample Biolife.Fds datafile
// The following code creates a TBindSourceDB which Live-Binds FDMemTable1
// to StringGrid1
//
// As a result, the column header texts will be the fieldnames of FDMemTable1's fields
// However, the code that determines the column on which to sort the StringGrid does not depend
// on this
BindSourceDB1 := TBindSourceDB.Create(Self);
BindSourceDB1.DataSet := FDMemTable1;
LinkGridToDataSourceBindSourceDB1 := TLinkGridToDataSource.Create(Self);
LinkGridToDataSourceBindSourceDB1.DataSource := BindSourceDB1;
LinkGridToDataSourceBindSourceDB1.GridControl := StringGrid1;
end;
procedure TForm2.StringGrid1HeaderClick(Column: TColumn);
// Sorts the STringGrid on the column whose header has been clicked
var
ColIndex,
FieldIndex : Integer;
AFieldName : String;
begin
ColIndex := Column.Index;
FieldIndex := ColIndex;
AFieldName := FDMemTable1.Fields[FieldIndex].FieldName;
Caption := AFieldName;
// Should check here that the the field is a sortable one and not a blob like a graphic field
FDMemTable1.IndexFieldNames := AFieldName;
end;
Note that this answer assumes that there is a one-for-one correspondence between grid columns and fields of the bound dataset, which will usually be the case for bindings created using the default methods in the IDE. However, Live Binding is sophisticated enough to support situations where this correspondence does not exist, and in those circumstances it should not be assumed that the method in this answer will work.

Delphi - Can you close all of the database tables?

Can you close all database tables except some? Can you then reopen them? I use an absolute database that is similar to BDE. If this is possible, how can I do so many?
Yes, of course you can. You could iterate the Components property of your form/datamodule, use the is operator to check whether each is an instance of your table type and use a cast to call Open or Close on it.
The following closes all TABSDataSet tables on your form except one called Table1.
procedure TForm1.ProcessTables;
var
ATable : TABSDataSet; // used to access a particular TABSDataSet found on the form
i : Integer;
begin
for i := 0 to ComponentCount - 1 do begin
if Components[i] is TABSDataSet then begin
ATable := TABSDataSet(Components[i]);
// Now that you have a reference to a dataset in ATable, you can
// do whatever you like with it. For example
if ATable.Active and (ATable <> Table1) then
ATable.Close;
end;
end;
end;
I've seen from the code you've posted in comments and your answer that you
are obviously having trouble applying my code example to your situation. You
may find the following code easier to use:
procedure ProcessTables(AContainer : TComponent);
var
ATable : TABSTable;
i : Integer;
begin
for i := 0 to AContainer.ComponentCount - 1 do begin
if AContainer.Components[i] is TABSTable then begin
ATable := TABSTable(AContainer.Components[i]);
// Now that you have a reference to a dataset in ACDS, you can
// do whatever you like with it. For example
if ATable.Active then
ATable.Close;
end;
end;
end;
Note that this is a stand-alone procedure, not a procedure of a particular
form or datamodule. Instead, when you use this procedure, you call it passing
whatever form or datamodule contains the TABSTables you want to work with as the
AContainer parameter, like so
if Assigned(DataModule1) then
ProcessTables(DataModule1);
or
if Assigned(Form1) then
ProcessTables(Form1);
However, the downside of doing it this was is that it is trickier to specify which tables, if any, to leave open, because AContainer, being a TComponent, will not have any member tables.
Btw, your task would probably be easier if you could iterate through the tables in a TABSDatabase. However I've looked at its online documentation but can't see an obvious way to do this; I've asked the publishers, ComponentAce, about this but haven't had a reply yet.

Delphi- How to Call ActionList on button click?

I'm making a multi-device application in Delphi XE8 which uses LiveBindings to a dataset.
There are a number of LB-specific Actions for FMX, including TFMXBindNavigateDelete. I'm trying to use this in a button-click handler like this:
Button Click Code:
procedure TForm1.Button1Click(Sender: TObject);
begin
if cdsOrdersSTATUS.Value='READY' then
begin
ShowMessage('Your Order Is Already READY/PENDING!');
end
else
begin
TAction(ActionList1.Actions[0]).Execute; //Not working,why?
end;
end;
The first (and only) item in ActionList1's Actions is my FMXBindNavigateDelete1.
The problem is, even if the code TAction(ActionList1.Actions[0]).Execute executes, the current dataset record is not deleted, so apparently
TFMXBindNavigateDelete's Action has no effect. Why is this, and how can I make it work?
Pic. ActionList1:
Actually, I think this is a good question and doesn't deserve the downvote.
I can reproduce your problem. I put two buttons on the FMX form. I set
Button1's OnClick to your Button1Click and Button2's Action to LiveBindingsBindNavigateDelete1.
Clicking Button2 pops up the standard 'Delete record?' confirmation and deletes the current record
if I answer "Yes", as expected.
However, when clicking Button1, even if your else block executes, the 'Delete record?' confirmation
does not appear, so the record has no chance of being deleted.
The reason is in the code
function TCustomAction.Execute: Boolean;
begin
Result := False;
if Supported and not Suspended then
begin
Update;
if Enabled and AutoCheck then
if (not Checked) or (Checked and (GroupIndex = 0)) then
Checked := not Checked;
if Enabled then
Result := ((ActionList <> nil) and ActionList.ExecuteAction(Self)) or
((Application <> nil) and Application.ExecuteAction(Self)) or inherited Execute or
((Application <> nil) and Application.ActionExecuteTarget(Self));
end;
end;
The Enabled property seems by default to be set to False during the call to
Update so the if Enabled then ... never executes. I haven't managed to find
a way to get Enabled set to True during the call to Update. Perhaps someone else knows how to do that.
In the case of Button2, execution then passes to TComponent.ExecuteAction and
it is the call to Action.ExecuteTarget(Self) in it which results in the
record-deletion routine executing.
So, from that, your problem seemed to me to become how to adjust the code so that
TComponent.ExecuteAction gets executed, in other words, how to associate the
Action with a component. The answer was fairly obvious.
All that's needed is this
procedure TForm1.Button1Click(Sender: TObject);
begin
if cdsOrdersSTATUS.Value='READY' then
begin
ShowMessage('Your Order Is Already READY/PENDING!');
end
else
begin
Button1.ExecuteAction(LiveBindingsBindNavigateDelete1); // <- this works
//LiveBindingsBindNavigateDelete1.Execute; //Not working,why?
end;
end;
I didn't understand exactly what you wanted to do but if you trigger the action by it's index, you can do something like this:
TAction(ActionList1.Actions[0]).Execute;

Shortcut triggers TAction on first created form instead of form with focus

I found (in Delphi 2010) that shortcuts always end up on first form (as owned by main form) that has that action, but not the currently focused form. My TMainFrm owns several TViewFrm. Each has a TActionManager with the same TActons.
I see some ways out, but wonder whats the best fix.. (and not a bad hack)
The forms are navigated using a tabset which calls their Hide() and Show(). I'd did not expect hidden forms to receive keypresses. Am i doing something wrong?
It seems that action shortcuts are always start at the main form, and using TCustomForm.IsShortCut() get distributed to owned forms. I see no logic there to respect hidden windows, should i override it and have it trigger the focused form first?
Disabling all TActions in TViewFrm.Hide() .. ?
Moving the TActionToolBar to TMainFrm but that is a pit of snakes and last resort.
I have found a workaround thats good enough for me; my main form now overrides TCustomForm.IsShortcut() and first checks visible windows from my list of editor tabs.
A list which i conveniently already have, so this might not work for everyone.
// Override TCustomForm and make it check the currently focused tab/window first.
function TFormMain.IsShortCut(var Message: TWMKey): Boolean;
function DispatchShortCut(const Owner: TComponent) : Boolean; // copied function unchanged
var
I: Integer;
Component: TComponent;
begin
Result := False;
{ Dispatch to all children }
for I := 0 to Owner.ComponentCount - 1 do
begin
Component := Owner.Components[I];
if Component is TCustomActionList then
begin
if TCustomActionList(Component).IsShortCut(Message) then
begin
Result := True;
Exit;
end
end
else
begin
Result := DispatchShortCut(Component);
if Result then
Break;
end
end;
end;
var
form : TForm;
begin
Result := False;
// Check my menu
Result := Result or (Menu <> nil) and (Menu.WindowHandle <> 0) and
Menu.IsShortCut(Message);
// Check currently focused form <------------------- (the fix)
for form in FEditorTabs do
if form.Visible then
begin
Result := DispatchShortCut(form);
if Result then Break;
end;
// ^ wont work using GetActiveWindow() because it always returns Self.
// Check all owned components/forms (the normal behaviour)
if not Result then
Result := inherited IsShortCut(Message);
end;
Another solution would be to change DispatchShortCut() to check for components being visible and/or enabled, but that might impact more than i'd like. I wonder whether the original code architects had a reason not to -- by design. Best would be have it called twice: first to give priority to visible+enabled components, and second call as fallback to normal behavior.

Delphi - TClientDataSet: Second call to applyupdates() does not apply the updates

Again I have a problem with the TClientDataSet.
I guess it's something really simple but I struggle on it for a while now.
Here's some code what shows what I want to do:
procedure TForm1.Button1Click(Sender: TObject);
begin
ClientDataSet1.Insert;
ClientDataSet1.FieldByName('anruf_von').AsDateTime := time;
ClientDataSet1.Post;
ClientDataSet1.ApplyUpdates(0); // without this applyUpdates in button2 works.
end;
procedure TForm1.Button2Click(Sender: TObject);
begin
ClientDataSet1.edit;
ClientDataSet1.FieldByName('anruf_bis').AsDateTime := time;
ClientDataSet1.Post;
showmessage(intToStr(ClientDataSet1.ChangeCount)); // returns 1
if ClientDataSet1.ChangeCount > 0 then
ClientDataSet1.applyUpdates(0);
end;
The code is self explaining I think.
When I press button1, a record is created and after the call to applyUpdates its written to the databse.
When I press button2, I want to make a change to this record and apply the updates to the database - and that doesn't work.
But when I comment out the applyUpdates in button1, the applyUpdates in button2 works correctly.
Try to change Provider.UpdateMode to upWhereKeyOnly, and set key field in Provider.OnUpdateData.
My gues is that insert works always since it is executed as
INSERT INTO ATABLE (anruf_von, anruf_bis) VALUES (...)
But update fails, since WHERE part will match DB stored time with time from clientdataset.
In fact, you will probably try to match two doubles, which is a no-no.
UPDATE ATABLE SET anruf_bis=<Time>
WHERE anruf_von=<WRONG Time, with more precision than stored in db>
When you set UpdateMode to upWhereKeyOnly, generated SQL sholud look like this
UPDATE ATABLE SET anruf_bis=<Time>
WHERE ID=<ID Value>

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