We have a windows program written in vbasic(i think) and we are re-writing the same program in c#. In the old program there is a grid. When we click any cell and as soon as edit the cell content the data in database is changing. In our new program we couldn't find the way of doing that. So we added some buttons for database actions like update selected cell.
What is the best way to do that?
You can do this in c# too.Use a datagridview and to bind with the database so that change in the grid effect database see here
Out of seeing dozens of legacy ODBC frontends put together in Access I would strongly advice not to commit changes in the database at real time. Instead try to create a lightweight process that helps the users to keep their data's quality high.
If you want this kind of functionality you could have the real time changes saved in a different schema, a set of different tables or with a flag that tells that these rows are unverified edits by the user X.
Rasel already gave you a pointer how to do the functionality in C#.
Related
I have an access database that has been used for many years, converted from Access 2000 to 2007 and was fine. In the last couple weeks it has been doing strange things!
There is a form for 'editing' a record. When the user clicked on the button to open this form, a small white box appeared and said 'Record Deleted'.
After that, the database was corrupted. I support this database and I can not even get into it in design view. When I try to open it (holding the shift key down while opening it), it takes a while, then it displays the Access design page that has the 'blank database' icon and to the right it lists the frequent opened databases.
So, I can't even get the to objects. The only option I had was to restore from a previous night backup. This meant the users lost all their work for the day. Today, one week later, it has happened again. All the users work was lost because I had to restore from backup.
I don't know where to begin to trouble shoot this since I can not get into it in design view when it has become corrupted. Looking for any suggestions to debug this. I can use a copy of the database I had restored.
Thanks
As a first and most important suggestion. You should split your database.You can do this from the database tools tab on top. By doing this you will have a seperate back end independat of the front end and your client will not loose any data as if they get the error / corrupted database it would not affect the data secured in the backend
Second I havent had the exact same error but in the past I have faced instances where the forms just dont work. a recommendation i read somewhere was to create a new blank form and copy over the elements from this form onto that and delete this form. I doubt if there is any problem with the VBA but it would be worth compiling the code to check.
Apologies if this does not help much, but I hope the first suggestions helps protect your client data in the instance your database crashes.
First, check if any automated VBA code or macro is running on OnOpen, OnLoad, OnCurrent, AfterUpdate, OnDirty, etc. events of the troubleshooting forms. Simply open the VBA window and look at code on the specific form's module. Or in the case of macros, open form in design view and check the Event tab of Property Sheet (and the same for specific buttons, textboxes, etc.). There may be DoCmd.RunCommands occurring when users interact with form controls.
Also, if you find yourself unable to open forms or deal with a corrupted database, consider beginning with a blank Access .accdb file and import all objects from the previous Access 2000 .mdb file. And if specific controls don't function properly, recreate them as needed.
As mentioned above, split your database between BackEnd (only tables) and FrontEnd (forms, queries, macros, modules) which prevents corruption, efficiently runs systems as only data is sent across the network and not whole application items, and overall fosters a better multi-user environment. Each user can have copies of the FE on their local machines but all will connect to one BE on a shared network. To help, Access 2007-2013 has a button for this on the Ribbon under Database Tools.
I'm using Siaqodb for my client side database engine in a Sync Framework silverlight project. I've switched to siaqodb because microsofts client side solution loads the entire database into memory at once and, as such, has a hard time handling large data.
I've bound a list of SiaqodbOfflineEntity objects to a silverlight datagrid in order to create an editable datagrid. Unlike microsofts solution, you can't bind the database entries directly to the datagrid. You have to query the database and bind a list of in memory objects to the datagrid. This causes a problem in that the database isn't immediatly updated when the datagrid cell is changed. I'm trying to find the best way to handle updates to the database after a change in the cell. I can't just update each item to the database because the siaqodb engine will mark the item as dirty even if no change was made to the object. This will cause conflicts when trying to sync. holding a cached version of the original list and then comparing each property of each object to find which ones have changed seems like it would work, but seems to be a bit cumbersome. I've also tried looking at some of the datagrids events but RowEditEnded doesn't appear to fire when a cell is edited and CurrentCellChanged seems to fire whenever I switch rows (odd).
There's got to be a better solution to this. Anyone have any ideas?
So I've gotten this to work by changing my offline entity classes to implement iNotifyPropertyChange and I think this is a reasonable solution. I set the PropertyChanged event to a function that saves the object to the database. There is a VS package called notifypropertyweaver that will inject this code at compile time, reducing the amount of work needed to be done on auto-generated entity code.
I am enhancing and fixing the forms/queries/VBcode etc. for an access 2007 database. The current version is being actively used and when I am done with my changes I need to transfer in my changes without disrupting the data stored in the tables already in the running mdb.
I'm not entirely sure how to handle the "merge" when the time comes. As an experiment I have a local backup copy of the version I started working on and used the import external Access data option. This imported the new forms, queries, vb, etc. But the only hang up is that the switchboard form isn't the new. Switchboard forms of course are guided by the switchboard manager but I was hoping that all that logic is held inside the form itself somehow. It seems this is not the case. After the import there is a new form of the same name with a number after it as expected, and the correct create/modify date. But when open it looks exactly the same as the old switchboard.
Any ideas?
It sounds to me as if you have both the data and the forms etc in the one database. This is not a good idea at all and if you are updating, it is the ideal time to correct the problem. If you split the database, any updates to forms and code can be simply copied to the user without worrying about the data. You will find some notes here: http://office.microsoft.com/en-us/access-help/split-an-access-database-HA010342026.aspx
The Access switchboard manager uses a table named Switchboard Items to dynamically populate switchboard form pages. You will need to transfer the updated version of that table to make your revised switchboard pages available in the other project.
Here's the story: I've been working on putting together an app in VS10 using Windows Forms in C++. This is my first experience with winforms, although I have a fair amount of experience with C++ and have worked with MFC a bit. The program needs to aquire data input from a hardware measurement system and the backend for that is mostly worked out. What I've been a bit stuck on is how to easily work with displaying this data in forms with the DataGridView and Chart objects. I'd also like to be able to save various sets of data and the programs current settings to disk that can be easily recalled and displayed in the program at a later point.
The solution I've been attempting so far has been to create a DataSet object for a certain program instance which holds some DataTables for the data and current settings. This is easily saved and read to XML files using the DataSet methods, which is nice. The tricky part for me using this method has been trying to sync up the program's display data and settings in the DataGridViews and Charts. It seems like these controls are really meant to be designed through the GUI. Maybe I'm just a noob, but I couldn't figure out how to get the DataSet I designed to link with my Charts using the "Add Project data source" dialog, so instead I set up a bindingSource and then proceeded to set Chart settings manually in the code. That's been getting hairy pretty quickly.
What would you have done to implement this, and how would you advise proceeding? I'm sure there has to be a much simpler way of doing this.
I've used Microsoft Chart Controls to display data from hardware measurement systems before with good results.
We store our data separately in arrays and when we want to display something, just call the AddXY function on the items to add a point. Configuring the graph in the first place is more easily done in designer though. Have a look at the samples for more info.
I am building a multiuser WPF application (requirement is a desktop app), database SQL Server 2008.
There are two types of users.
The first type user will enter a record which would be stored in a table.
The second type user initially will be presented with a listbox with the records from the table. The requirement is that the listbox must be updated live (i.e. if a new record is entered by the first user the listbox must be updated).
Currently I have not yet implemented the Database functionality.
I am currently working with ObservableCollection and simulating this scenario.
I would like to know the best approach for achieving this.
Should i use a timer and keep querying the table? Is there a more efficient way?
Is this even possible (should I switch to ASP.NET?) ?
I would appreciate any suggestions and tips that you may have.
Try using SqlDependency, since it can raise an event (OnChange) in your code when the results of a query would change on the server (as the result of an INSERT or UPDATE from another user or process, for example)
An example of its use on CodeProject for a simple live chat application:
http://www.codeproject.com/KB/database/chatter.aspx