I'm a beginner with ASP.NET and webapplications in general.
For a project I have to interact with an enginnering software to read some data, for this I have to to use a ASP.NET project based on the .Net Framework 4.8.
For now I called these functions with buttons and displayed the data in gridviews. The problem is I want to show the data on all clients and the data should still be there when I refresh the page on one client.
To load some data in the gridview I tested it by using a function like this.
Load data to datagrid
The problem is I can't see these changes on other clients.
Is there a way to implement this?
Well, running some in-memmory code for one user of course will not work for other users. You probably would be best to write a seperate console application, place it on the server, and then say schedule it to run ever 5 minuites or whatever. That console or desktop program would thus then write out the data to a database table. Now, any and all web pages (and users) can now have a grid display that quieres against that database.
The other possbile (if for some strange reason you wanted to avoid a database to persist and store this information?
You could consider using signalR. It is complex, but allows you to push (send) out information to all web clients connected to your system. This involves some rather fancy foot work, and does require your web page to include some JavaScript. As a result, the simple database idea is less work, simple, and does not require many hand-stands.
but, signalR is what is used for say pushing out information to each client browser, you can get started here, since this is a vast topic well beyond that of a simple Q & A on SO.
https://learn.microsoft.com/en-us/aspnet/signalr/overview/getting-started/
Related
I am working on an application where users in a local network are notified when a "record" from the database changes. So if person "A" changes Record 1 and person "B" has Record 1 in their view, person "B" will be notified that Record 1 has changed.
We are currently using what is called a "duplex" service to send these notifications through a WCF service. The service is rather slow and ideally we would like to remove it. Are there any ways to keep data in real-time (or close to it) for users, when another user has updated the database?
If you are just looking to replace your notification service my suggestion would be to use SignalR to keep your clients synchronized with your DB.
I had a similar problem once and ended up crossing over to a NoSql cloud solution called Firebase with the Firesharp library. Firebase - Features, Firesharp.
It is blindingly fast and actually really easy to use. So if your application is still quite small and the business risk of migrating to a NoSql setup is small it might be a worthwhile solution.
How long they keep the record in view?
What is the mechanism that is checking if the value changed?
what kind of client application are you using?
You could create an async method that is validating the status of the item the user is using against a nodejs server that will be querying the db, for that particular record, reply with the value and the async method can validate if the current value is different from the one from the DB and then it can inform the user or update the record.
Those have small footprint and should run more efficiently.
As per requirement, we need to convert the existing MS Access database to a web application. Is there any easy way to convert the MS Access database to web application? As of now they are inserting the data to access db using access Forms. User also wish to continue access form feature even if we create new web application for the same. That means user should have the option to access the MS access database through Access forms as well as web application.
Please guide me away to solve this issue.
Best Regards,
Ranish
You can use Office 365 and have somewhat of a web-based application.
https://blogs.office.com/en-us/2012/07/30/get-started-with-access-2013-web-apps/
Or, store Access in SharePoint, but your functionality will be quite limited. Keep in mind, no VBA will run on a web-based application.
The alternative is to use SQL Server Express, and ASP.NET, both of which are free from Microsoft. I'll tell you now, though, the learning curve will be quite steep if you have never used these technologies before. This combo, however, will give you the most control!
You can get the .NET framework from here.
https://www.microsoft.com/en-us/download/details.aspx?id=30653
You can get SQL Server Express from here.
https://www.microsoft.com/en-US/download/details.aspx?id=42299
Four years after and according to this:
https://www.comparitech.com/net-admin/microsoft-access/
still a question for many. Access can be converted to an Web App in almost no time. Particularly Access Forms are super easy to crate with the library like Jam.py.
The process was discussed on Reddit in April 2021:
https://www.reddit.com/r/MSAccess/comments/mj4aya/moving_ms_access_to_web/
I see quite a few Access databases with more than 100 tables, all converted successfully to SQLite3. After inspecting the imported tables via provided link, Forms are automatically created. Which leaves the Access Reports and Business Logic untouched. Reports can be designed in LibreOffice for Jam.py as Templates. Business Logic can be moved from VB to Python, if there is a need to do so.
The SQLite was selected as the default DB for the conversion, since it is very portable. Looks like the converted App can be moved to any DB that Jam.py supports, by Export/Import.
Cheers
First of all, Database and Web Application are not mutually exclusive.
Back to original question, I have done multiple projects like that. A client started with small Microsoft Access database with a couple of user; then they migrate to to web application when they get more traffic.
At first, you want to convert data from MS Access Database to SQL Server. MS Access Database is not meant to access multiple users simultaneously. Then you develop the Web Application which uses SQL server as back end database.
Right before you go live, you convert the data again from MS Access Database to SQL Server very last time. Then do not let them use old MS Access Database anymore.
Easy way to convert the MS Access database to Web application
Most of the time whoever created MS Access database are not software engineer, so table are not normalized and do not have relationship at all. I normally create new normalized database in SQL Server. Then write a small program to convert those data from MS Access to SQL database.
There are generally two approaches with more details covered in this article looking at ways to convert microsoft access to web application
Direct Port means simply a basic migration whereby you port more or less verbatim basic Access forms into a web portal i.e. Microsft Access to a browser-based version as is using a third-party tool. Some of these are quite mundane in that it just allows you to run the Access application inside an internet browser (whoopee!) or can be quite drawn out and then limits you on how much you can change afterward. With even more complex cases requiring a consultant to help you migrate the system. Though it does help to know your user count as the higher you tend to be, the less appealing a third-party porting service becomes due to subscription-based models.
Upsize -the more involved or complex your data structure is an upsize using custom development and splitting the system across web and data tiers might be worth it if
You've got a special process or some secret sauce you're looking to keep.
Likely going to have a significant user count and want to avoid subscription
Inherently cynical or cautious, and want to handle your own architecture and security
Looking for a specific user experience
If you mean how to convert automatically and you want to keep both Access and the Web application (I don't recommend that, I would move everything to the Web app) I would do the following:
Export your Access data in CSV/Excel
Use a platform like DaDaBIK to import the CSV/Excel file and automatically create a Web app based on that file, with data stored on SQL server, MySQL, PostgreSQL or SQLite.
connect your Access to the SQL Server (or Mysql, ...) database created by DaDaBIK, from now on Access will only be used as a frontend.
Now you have a web app created with DaDaBIK and your Access frontend both working on the same DB. As I said I would skip 3) and keep only the Web app, this helps with handling data integrity when two users are accessing the same record.
Depending on how complex is your Access Application (e.g. complex validation rules or custom VB code you added), you could reach your goal without any coding or with some coding.
What I want to do is this: create an ASP.NET MVC web app that periodically looks for new or updated data from an external API (eg, a new order created or modified in an inventory management system), and then sends this data to another system. Similar sort of thing to this - I have tried using it, but I've found it's a bit too limited for some of the things I wanted to do.
I am currently trying to figure out the best way to go about this. I imagine that it will work like this:
Periodically (using a timer?) pull the data from one system's API, and cache the id and DateUpdated fields (in a local database I assume) for each item.
If there are any changes against the cached data, then convert the item to appropriate format if needed and post to the second API.
I would be connecting to a few different third party systems, which for the most part do not support web hooks etc, so I assume polling and caching is the only option.
Am I on the right track? Haven't been able to find a lot of resources on this sort of thing, so would appreciate any advice.
how to update the gridview automatically without using timer control when there is a change in database table.
please let me comment if anyone can't get my question .
thanks in advance
In order for the application to detect a change in the database it must either monitor the relevant tables or somehow be notified of changes in the database by an outside source. Using a timer to poll the database for changes is one option. Having another program perform that task and then notify your application is another way to do it. Some databases, like Firebird, has the ability to post events that your application can listen to.
In my experience having the database post events is by far the easiest solution but it of course requires you to use a database with that capability. You should probably also consider your design. Why do you need the database to notify the GUI? Is it really necessary or just an easy way to have the GUI updated? Take some time to think about what roles the different layers in an application should fill before deciding on this strategy.
That being said sometimes having the database instigate GUI changes or other actions is perfectly acceptable. If the database is shared amongst multiple users and each user needs to be notified of actions taken by the other users it could be a good solution. Personally I'd try to find other ways of communicating before settling on the data driven approach but in some cases ther's really not that many other viable options.
actually when the application needs it queries the database but in this situation the database needs to cause events.though the database can cause events using triggers but that has some limitations and the scope of the change taking place is limited within the database.to show a change in the application(here updation of gridview) can only take place if a call is made from the application only.this can be done using timer controls from the application .but without sending a call to the database from the application its impossible
You can use windows service that will run offline from the application...
The service will query the db and will update file in the system when there is a change...
In the application you can use cahce dependency on the file.
I'm not 100% sure, but I think you could look into Windows Communication Foundation and some of the examples they they have.
What is the most effective way to sync two identically structured DataSets using a Web Service?
The design I use at the moment is simple without a Web Service. All data iscached on the Client, and it will only update data from the MySQL database if an update has been done, this is determined by a timestamp.
If possible I want to keep the same simple design, but add a Web Service in the middle, to allow easier access to the database over our limited VPN.
Best Regards, John
That's one heck of a question, but something I'm doing myself too. Easiest way I guess would be to add a "saved version" property. If it really is a simple design then you could just re-write only the DAL code to get things working for a web service. In fact, if the WSDL is done right, you may only need to make very minor adjustments (especially if the DB was previously designed using EF).
You say you want to sync two datasets simultaneously, but the question I guess is why? And which two? Do you have two web services, or are you wanting to sync data to both the local cache and the online web service (MSSQL db?) simultaneously?