I have an TRxQuery in Delphi 5 (which descends from TQuery) bound to a grid. I'm adding a filter edit box and want to filter the grid as the user types. Is there a way to filter the dataset without closing and reopening the query as this causes an unwanted flicker.
Many thanks
Procedure SetFilter(DS:TDataset;Const Filter:String);
begin
DS.Filtered := false;
DS.Filter := Filter;
DS.Filtered := true;
end;
Related
I connect TFDQuery with TStringGrid in live binding in delphi firemonkey apps.
I tried to use filter in TFDQuery based on Editbox for searching purpose, and it's work just fine.
but, whenever I clear the Editbox, one of my row in TStringGrid would show "(bcd)" as it's value like the pict below.
what am I doing wrong ? how can I fix it ?
Edit :
Im using mySql database with firedac tfdconnection + tfdquery
the datatype of the column is AnsiString & FmtBCS(32,0)
Im using live binding feature in delphi.
my filter code
with MainQuery do begin
Filtered := False;
OnFilterRecord := nil;
Filter := FilterValue;
Filtered := True;
end;
I Insert to the table with TFDConnection.execSQL
the "(BCD)" part always change on the selected Row as the pict below.
EDIT 2:
To Reproduce my error, you can :
add TStringGrid.
Add Editbox.
add tfdconnection
add tfdquery
use live binding from tfdquery to tstringgrid.
add query to tfdquery.sql.text that using SUM() in mysql. Example : "select id, sum(stock) as total_stock from stocks"
activate that tfdquery
add onkeyup event on editbox.
add this code :
FilterValue:= 'garmines_id LIKE ''/' +Edit1.Text+'%'' ESCAPE ''/'' ';
with FDQuery1 do begin
Filtered:= false;
OnFilterRecord := nil;
Filter := FilterValue;
Filtered := True;
end;
run
try to type something on editbox to make sure filter works fine.
clear editbox, then the "(BCD)" is show on the selected row.
I reproduce this error. this is the SS :
Well, I still don't know what exactly causing this problem but I found the work around solution that avoid this problem appears.
you need to set TStringGrid.selected value to -1 before refreshing the TFDQuery. so the code become :
FilterValue:= 'garmines_id LIKE ''/' +Edit1.Text+'%'' ESCAPE ''/'' ';
StringGrid1.selected := -1;
with FDQuery1 do begin
Filtered:= false;
OnFilterRecord := nil;
Filter := FilterValue;
Filtered := True;
end;
I suspect that the cause of this problem is data type that come from mysql sum() method namely FmtBCD(32)
Go to DataMapping Rules (firedac connection)
Mark ignore inherited rules
create 2 new rules
rule1: source: dtBCD / target datatype: dtDouble / all min: 0 / all max: 100
rule2: source: dtfmtbcd / target datatype: dtDouble / all min: 0 / all max: 100
click ok. now the fields will be dtDouble, and are compatible with tgrid
I have a DataSet (TZQuery), which has several boolean fields, that have TDBCheckBoxes assigned to them.
These CheckBoxes have "OnClick" events assigned to them and they are triggered whenever I change field values (which are assigned to checkboxes).
The problem is that I do not need these events triggerred, during many operations i do with the dataset.
I've tried calling DataSet.DisableControls, but then events are called right after i call DataSet.EnableControls.
So my question is - is there a way to disable triggering Data-aware controls events.
Edit (bigger picture):
If an exception happens while let's say saving data, i have to load the default values (or the values i've had before saving it). Now while loading that data, all these events (TDBCheckBoxes and other data-aware controls) are triggered, which do all sorts of operations which create lag and sometimes even unwanted changes of data, i'm looking for an universal solution of disabling them all for a short period of time.
Building on Guillem's post:
Turn off everything:
Traverse each component on the form with the for-loop, shown below, changing the properties to the desired value.
If you want to later revert back to the original property values, then you must save the original value (as OldEvent is used below.)
Edit: The code below shows the key concept being discussed. If components are being added or deleted at run-time, or if you'd like to use the absolutely least amount of memory, then use a dynamic array, and as Pieter suggests, store pointers to the components rather than indexing to them.
const
MAX_COMPONENTS_ON_PAGE = 100; // arbitrarily larger than what you'd expect. (Use a dynamic array if this worries you.
var
OldEvent: Array[0.. MAX_COMPONENTS_ON_PAGE - 1] of TNotifyEvent; // save original values here
i: Integer;
begin
for i := 0 to ComponentCount - 1 do
begin
if (Components[i] is TCheckBox) then
begin
OldEvent[i] := TCheckBox(Components[i]).OnClick; // remember old state
TCheckBox(Components[i]).OnClick := nil;
end
else if (Components[i] is TEdit) then
begin
OldEvent[i] := TEdit(Components[i]).OnClick; // remember old state
TEdit(Components[i]).OnClick := nil;
end;
end;
Revert to former values
for i := 0 to ComponentCount - 1 do
begin
if (Components[i] is TCheckBox) then
TCheckBox(Components[i]).OnClick := OldEvent[i]
else if (Components[i] is TEdit) then
TEdit(Components[i]).OnClick := OldEvent[i];
end;
There may be a way to fold all of the if-statements into one generic test that answers "Does this component have an OnClickEvent" -- but I don't know what it is.
Hopefully someone will constructively criticize my answer (rather than just down voting it.) But, hopefully what I've shown above will be workable.
One way to do this is following:
var
Event : TNotifyEvent;
begin
Event := myCheckbox.OnClick;
try
myCheckbox.OnClick := nil;
//your code here
finally
myCheckbox.OnClick := Event;
end;
end;
HTH
The internal design of the TCustomCheckBox is that it triggers the Click method every time the Checked property if changed. Be it by actually clicking it or setting it in code. And this is happening here when you call EnableControls because the control gets updated to display the value of the linked field in your dataset.
TButtonControl (which is what TCustomCheckBox inherits from) has the property ClicksDisabled. Use this instead of (or in addition to) the DisableControls/EnableControls call. Unfortunately it is protected and not made public by TCustomCheckBox but you can use a small hack to access it:
type
TButtonControlAccess = class(TButtonControl)
public
property ClicksDisabled;
end;
...
TButtonControlAccess(MyCheckBox1).ClicksDisabled := True;
// do some dataset stuff
TButtonControlAccess(MyCheckBox1).ClicksDisabled := False;
Of course you can put this into a method that checks all components and sets this property if the control inherits from TCustomCheckBox or some other criteria.
Hi I am using KBmmemtable in a small project and come across a small speed issue i cannot seem to fix.
Basically I have a field in the table which has a boolean value, the table has about 100 records in it. If I itterate though the records in the table setting the value of the field to true it does it very quickly, however if I set a filter on the table and then itterate through the filtered records it takes about 10 times longer even though there could only be 10 records to iteerate through.
Anyone got any ideas
The code I am using is
DM1.DS1.Enabled := False;
with DM1.DS1.DataSet do begin
First;
while not Eof do begin
edit;
Fields[18].AsBoolean := TickState;
// FieldByName('Selected').AsBoolean := TickState;
post;
next;
end;
end;
DM1.DS1.Enabled := true;
I do have an index on the field, I have also tried it without an index
thanks
colin
There is a way to use a filter on a kbmMemTable and make it work really fast...
Set kbmmem.Filtered:=true;
and dont use the Filter property, instead use the OnFilter Event...
procedure Tform1.kbmmemFilterRecord(DataSet: TDataSet;
var Accept: Boolean);
begin
Accept:=Fields[18].AsBoolean;
// when you iter your table you would see only thouse rows having "true"
// on the field "Selected"
end;
and yes dont forget to DisableControls before the while...
with kbmMem do
try
DisableControls;
Filtered:=true;
First;
while not eof do
begin
// do your stuff here
Next;
end;
finally
EnableControls;
end;
This is a suggestion for the loop, it should not take any longer than with an unfiltered kbmMemTable:
with kbmMemTable do
begin
First;
while not EOF do
begin
//do something, but don't change the position of the record-pointer!
//if you do some writing to the record, be sure to
// enable "AutoReposition" in your kbmMemTable
Next;
end;
end;
Disabling the DataSource is not such a good option. Every Component attached to the DataSource is then "empty" and must be refreshed. You get a lot of problems if you use recursion or more than one "disabling" of a DataSource. Same, when you enable the DataSet. With DisableControls you signal all the attached components, that they must not update data. With EnableControls, this condition is ended and the controls are refreshed. Another advantage is, that there is a counter incremented with every DisableControls and decremented with every EnableControls. So you can call this multiple times (for example in an recursion) and only the last call of EnableControls finally enables the controls.
information:
I have an order form.
With "keuze" and "aantal" it wright a new line. The Orderline gets an OrderID.
But the user may only see the orderline from his OrderID.
How can i make it work that it only shows, for example the OrderID "47" ?
procedure TfmOrder.btInvoerenClick(Sender: TObject);
begin
dm.atOrder.open;
dm.atOrder.Append;
dm.atOrder ['OrderStatus'] := ('Aangemeld');
dm.atOrder ['klantID'] := fminloggen.userid;
dm.atOrder ['OrderDatum'] := Kalender.date;
dm.atOrder ['Opmerkingen'] := leOpmerkingen.text;
dm.atOrder.post;
cbkeuze.Visible := true;
dbRegel.Visible := true;
leAantal.visible := true;
btOpslaan.Visible:= true;
end;
This is the code for making a new Order
procedure TfmOrder.btOpslaanClick(Sender: TObject);
var orderid:string;
begin
dm.atOrderregel.Open;
dm.atDier.open;
dm.atorderregel.Append;
dm.atOrderregel ['AantalDieren'] := leAantal.text;
dm.atOrderregel ['OrderID'] := dm.atOrder ['OrderID'];
dm.atOrderregel ['Diernaam'] := cbKeuze.Text;
dm.atOrderregel.Post;
leaantal.clear;
cbkeuze.ClearSelection;
end;
And this for a new orderline
thanks in advance
I know got a different error using this code:
begin
dm.atorder.Open;
dm.atorder.filter := 'KlantID = ' + (fminloggen.userid);
dm.atorder.filtered := true;
while not dm.atorder.Eof do
begin
cbOrder.Items.Add (dm.atorder['OrderID']);
dm.atOrder.Next;
end;
dm.atOrder.Close;
end;
It gives an error: The arguments are from the wrong type, or doesn't have right reach or are in conflict with each other.
here is userid declared.
var Gevonden: boolean;
userid : string;
begin
dm.atInlog.open;
Gevonden := false;
while (not Gevonden) and (not dm.atInlog.eof) do
begin
if dm.atInlog['email'] = leUser.Text
then
begin
Gevonden := true ;
inlognaam := dm.atInlog['email'];
userid := dm.atInlog['KlantID'];
end
else
dm.atInlog.Next
end;
this is obviously in another form
You can use the Filter property of the data set:
atOrderregel.Filter := 'OrderID = 47';
atOrderregel.Filtered := True;
You can add the grid's columns property statically in the object inspector, showing only the fields you need. If the columns list is empty (default) it is filled with all available fields.
Just add as many columns as you need and link each column to the corresponding field. You can reorder the columns and set the widths and titles individually. There are still some more properties available which are worth to explore.
Im assuming your grid is bound to a datasource component. This datasource is then linked with a TDataset descendant. There are a couple of ways you could acheive the desired filtering of the dataset to display only orderid 47.
Firstly, you could set the Datasets SQL property to contain a (server side) SQL query such as:
SELECT * from table WHERE OrderID = #OrderID
You would also need to create a parameter in the dataset to pass the (changing) value for the required OrderID. So add a new Parameter to the dataset (#OrderID), and then at runtime you can set this parameter value in code, something like:
DataSet.Parameters['#OrderID'].Value := ParameterValue;
Alternatively, you could also FILTER the dataset (client side) to just show the correct data:
Set your SQL property of the dataset to retrive the entire table, something like:
SELECT * FROM table
And then at runtime you could set the Filter property of the dataset to only get OrderID 47:
Dataset.Filter := 'OrderID = '+InttoStr(ParameterValue);
Depending on your needs one method may suit better (performance/memory) wise.
As Najem has commented, there is also a third method - using a Master-Detail dataset relationship. This method works using two datasets, one is the master of the other. When the master table record is changed, the detail dataset is then filtered using the value defined in the Key or MasterFields property of the M-D relatioship.
If you are connected to some datasource you could always create a SQL Query. Something like:
SELECT * FROM YourDBTable WHERE OrderID=47
I have a TTable, and I am loading CSV files to this TTable. Three fields are there: Id, Hits & Path.
I made some lookup fields to this TTable with another query.
I want to sort the table. I am getting the message "Capability not supported." when I try to call AddIndex('ndxHits','HITS',[]);
Here is my code:
with DM.TblCVResults do
begin
try
Active := False;
TableName := 'C:\CSV\123.txt';
Active := True;
AddIndex('ndxHits','HITS',[]);
AddIndex('ndxCandidate','LkCandidate',[]);
AddIndex('ndxLastCV','LkLastCV',[]);
AddIndex('ndxPostCode','LkPostCode',[]);
IndexDefs.Update;
Active := True;
DM.TblCVResults.IndexName := 'ndxHits';
except
on E: Exception do
MsgError(E.Message);
end;
end
Your previous question mentioned you were using ttASCII as the TableType. ttASCII tables, AFAIK, don't support indexes.
Your best bet is to load the ttASCII TTable content into a TClientDataset` (CDS), which does support indexes. I haven't tested with a ttASCII table as the source, but it should be as simple as:
Add a TDatasetProvider component to your application. Set it's DataSet property to your TTable.
Add a TClientDataSet component to your application. Set it's ProviderName to the DataSetProvider you added above. (I've named it CDS in the steps below.)
Open both the Table and the ClientDataSet (CDS), in that order.
Table1.Active := True;
CDS.Active := True;
Turn off updating of the TTable if you don't need it. (It's much faster.)
CDS.LogChanges := False;
Run the following code to create the indexes:
// Repeat for each additional index
with CDS.IndexDefs.AddIndexDef do
begin
Name := 'ndxHits';
Fields := 'Hits';
Options := [];
end;
Set the ClientDataSet's IndexName property to the index you want active:
CDS.IndexName := 'ndxHits';
Use the ClientDataSet like you would any other dataset. Search it using Locate or FindKey, add to it using Insert or Append, filter it, and so forth.