I have two ADO Tables linked as master/details tables, tblCategory (master) and tblItems (details). Both tables have its own grid, and displayed in the same form. I also have data aware controls (dbedits).
Say, currently I'm at: Category=Books, No of Items=10 records, and pointing at record number 5 in the grid. I want to add a new record to the item, so I use:
tblItems.Insert;
The problem is, instead of adding a new row, the grid and the db aware controls are showing the current record (rec No 5). Not inly that, it seems the record is in edit mode too. After I cancel it and repeat the Insert command, only then the new row appeared.
How to fix this, so each time I use tblItems.Insert it always add a new and empty row :)
Nevermind, I think I know what caused it. It's the db aware controls. After the insert command, user will input data. This makes the db aware control receives focus and it automatically sets its position to the current record and displays it.
The solution is to use non-db-aware controls instead, and set the behavior programatically
Related
oracle 10.4
devart dotConnect - 6.50...
MVC2 project - web page
User fills out form, then controller gets new entity, fills it out. saves database
System_id before saving = 0 (its an int/number - so no cannot be null)
Several other tables linked, so they have their own System_id as well.
When it gets saved to database, some trigger (there is a stored trigger for the table, which I only seam to understand as when system_id=null to be fired), a new Number is assigned for System_id.
This all worked fine.
Then I came along, and needed some updates.
Another field needed on this "main" table
(I have earlier, added columns to another table, with out issue)
Added column to this "main" table (restrict_to_me)
Now when it tries to save to database - it trys saving "system_id=0".
Linked tables, also make records with system_id=0
In entity framework designer - i can see the field system_id ENTITY_KEY=true and StoredGeneratedPatern=Idenity
So I can not see what I have done to stop somthing from working with the entity framework, except updating the entity framework.
Any direction much appricated
thanks
When you added the new field, did you drop the table and recreate it?
If you did that then you deleted the trigger at the same time. So when you recreate the table, you also need to recreate the trigger.
Try inserting data just using an SQL statement and see if the id is generated.
This was an Entity Framework issue, one many have already had.
Not every time, but some times, when updating the model, StoredGenereatedPattern being droped in a section.
http://www.ladislavmrnka.com/2011/03/the-bug-in-storegeneratedpattern-fixed-in-vs-2010-sp1/
When looking at fixes, did not understand that BOTH SSDL and CSDL parts stored in same text.
So look in upper part that it has StoredGenereated Pattern.
I am making a app in Delphi 6 + MySQL database using standard data-aware components and dbExpress. The app allows a users to view records in a grid and edit data (insert and/or delete records) client side. These data edits are then only written to database on clicking the submit button. All of this works fine and has the following setup:
Controls:
1. DBGrid1 linked to a DataSource1 to display data visually.
2. DataSource1 is linked to ClientDataSet1 to offer data for DBGrid to display.
3. ClientDataSet1 is linked to DataSetProvider1 to provide client-side data for editing.
4. DataSetProvider1 is linked SQLDataSet1 which selects records from a single DB table.
5. SQLDataSet1 is linked to SQLConnection to provide connection to MySQL database.
Actions:
1. User inserts a record: I use ClientDataSet1.InsertRecord;
2. User deletes a record: I use ClientDataSet.Delete;
3. User submits data: I use ClientDataSet1.ApplyUpdates(-1);
This all works great in terms of handling data & posting data (with the inclusions of a small hack on DataSetProvider1BeforeUpdateRecord to delete records).
NOW FOR MY PROBLEM:
When the user first loads the form, the DBGrid1 displays all original records, removes all deleted records. But when the user inserts a new record in ClientDataSet1, a blank record is displayed in DBGrid1. The actual data is not lost or set as NULLS as when you ClientDataSet1.ApplyUpdates, this record is correctly written to the DB.
I know TClientDataSet has a data property for original data and a Delta property for edited data. Can these two properties with data by displayed in a single DBGrid at one time & still allowing the user to edit the data?
I have looked at 30+ resources and demo apps & all avoid this issue. Can this be done?
Ok...this question has been viewed a fair amount without much feedback. I did some research by downloading many tutorials, demo apps & read multiple articles/help info discussing the use of these controls.
The net result:
These controls are a bit buggy in general.
In specific reference to my question, it is safe to say the controls cannot do what I describe as a standard.
This is based on the 30+ demo apps, articles and tutorials I reviewed that either don't describe displaying both the original data with Delta data in a single data grid. Sure you could hack this outcome (which is what I did) using a Listbox or StringGrid, but that also indicates the control cannot or not usable at providing this functionality (on the slim chance it might).
This functionality is an obvious oversight in my opinion as a user wants to see the potential outcome of their actions, conveniently in a single data grid AND a developer wants to provide that in a simple & pain free way i.e. using a datagrid to display data!
Question Answered [if you can prove differently with a demo app that I want to review, I will remove this].
If you created a demo app and couldn't get it to work, up vote my answer. Thanks
The TDBGrid control provided with Delphi does not have the built-in functionality to display both the old and new values for fields. You are welcome, of course, to inherit from the Grid or create your own and add the functionality, or buy a third party component that accomplishes what you want. You are not limited to the standard controls, though they do provide the most commonly required functions.
You can also accomplish what you want by using calculated fields. For example, if you have a String field Name, add a new calculated String field to the dataset called OldName, with the same length as Name.
Then in your OnCalcFields event for the dataset, simply enter code like the following:
if DataSet.State = dsEdit then
begin
DataSet.FieldByName('OldName').Value := DataSet.FieldByName('Name').OldValue;
end
else
begin
DataSet.FieldByName('OldName').Value := Null;
end;
TClientDataset will handle itself the correct record status. Changes are logged, but unless you ask it explicity to show some other status (see StatusFilter property), it will show the actual state of a record.
It is possible InsertRecord bypasses some notification mechanism, so the field display is not updated. What if you perform simpy an Insert and the set field values?
In my application I have a TcxGrid (devexpress datagrid) that displays the data returned from a stored procedure.
Now I would like to add a column showing checkboxes from which the values cannot come from the database but are calculated internally.
When the checkboxes are clicked, some internal logic needs to be triggered.
Any suggestions?
#boris, I recommend you use the Support Center site of DevExpress for this type of question, there are thousands of articles to DevExpress products.
Anyway I leave here a link to something that might help ;)
How to set up an unbound item in a data-aware View
Are you creating the view at runtime or at designtime?
I sort of cheated when I did this at runtime, and returned a static value as one column from my query:
select false as processed,col1,col2 from table where true
I could then safely attach the dataset, and I had my new column to play with.
You would then perhaps use the properties.onChange or properties.onEditValueChanged for your logic code.
I'm coming from the delphi world and I want to make a master/detail interface, like Order and Products.
I already made actions to display the data using fields and a jqGrid. What I want know is how make possible to add lines, edit or remove them, but, just make the changes in db when the user confirm the changes in the master.
On delphi I would use a TClientDataSet with all the in memory changes and just after the confirmation would execute them inside a transaction like:
BEGIN
Master.Post
FOREACH Line IN Lines Line.Post
COMMIT
So in resume, I don't know how keep in memory the array of lines in the grid and how send them back to server to commit.
Any help will be appreciated. Thanks in Advance.
You'll need to keep track of the changes client side, perhaps using some hidden fields and/or form fields in your grid. When a line is deleted (that previously existed in the db), you'll need to add it's id to a field containing lines to delete. Lines that are added need to have associated form fields containing their data. When the master is committed you roll the whole set of fields up into a POST and send that back to the server.
Using LINQ to SQL, you'd create a data context, get the master object, then delete the related objects (from the hidden field of ids) that are so marked and create/add new related objects that didn't exist before taking the values from the appropriate form fields. Then you'd do a SubmitChanges and all of the statements would be executed within a single transaction.
Set the scene:
New to .NET; drinking from firehose
ASP.NET MVC app, SQL Server back
Editable table in browser with a single SAVE button.
User can right-click to add or delete rows.
Table won't ever have more than approx. 30 rows.
My question :
I'm saving everything upon the Save button click but would it be better to save row by row, AJAX style, as the user makes updates?
I don't like the look of separate buttons for each row, which is why I've designed it this way.
Is this mostly a UI issue? Am I missing any technical gotchas here, such as backend failure during the mass saving of the rows?
Additionally, assume I do save the entire table at once, is it better to create an ADO DataTable object or just loop through, inserting/updating each row as I go by calling a stored procedure. I suppose I could add LINQ to the firehose, but that would make this question even less "answerable".
You don't have a huge volume of data here, so saving all 30 rows at the end of the table is a reasonable approach. But you should be prepared for a failure, particularly if you are changing existing rows when it will fail more often due to other apps/users changing the same data. Just make sure that you wait for confirmation from the SQL server that the changes have been committed.
What I've done before with these sorts of big table views is when somebody clicks on a cell they'd like to edit, run some ajax to display a text field with that text, they can edit, then listen to onmouseout and the enter button to send off the ajax request to modify the single row.
When the response from the ajax call comes back you can add a tooltip or something that it was saved, and then change the cell to the new val.
Assuming you have SQL2005, you could build up an XML document with all of your data rows, then call a single stored proc and pass it your XML. Then the stored proc could save all of the rows at once.