Pre-installed data on LongListSellector - c#

I've got an ObservableCollection which is binded to my LongListSelector.
User can add items to it by form in my app - all data saved in list are serialized.
I want to add few items to my app, that will be present after installation. User can delete and modify them, like any other items.
What is the best way to do that? I don't think that creating multiple objects in code is good idea.

Local databases are what you need. They would even be helpful later of you plan to persist the changes user has made.
Windows Phone Silverlight has nice LINQ-to-SQL support with SQL server CE. Here's the information you'll need to implement databases: http://msdn.microsoft.com/en-us/library/windowsphone/develop/hh202860%28v=vs.105%29.aspx
If you prefer app walkthrough, here it is: http://msdn.microsoft.com/en-us/library/windowsphone/develop/hh202860%28v=vs.105%29.aspx
You will need to deploy a reference database and copy it to isolated storage since you want user to have some data prepopulated. Here's a nice reference for such scenarios: http://msdn.microsoft.com/en-us/library/windowsphone/develop/hh286411%28v=vs.105%29.aspx
Edit: You can, of course, use external XML, but it has its fair share of problems like this.

Related

Have Users Interact with MS Access Queries instead of Tables

I am working on a project where I need to create a database to track the status of units throughout the production process. My current blockade involves getting the users to interact with a DataGridView that is supplied from a Microsoft Access Query instead of a Microsoft Access Table.
What I want to do is create a query in Microsoft Access and have it link to the DataGridView so end users can interact with a query instead of the actual tables, while populating all parent tables.
I am not sure if what I am attempting to do is possible or advised. This is the first time I have built a database in the professional world and want to make sure I am doing things properly. I have also never built a C# application for business use and have very limited experience with the language itself.
I have tried creating the Query in Access and linking it to the application in the same way you would add a table from a data source. That would allow me to view the data in the query...but it would display as a read-only and not allow for any data to be altered (the query builder in the TableAdapter Query Configuration Wizard indicated it was a read-only) . I have tried adding all related table adapters to the TableAdapterManager and it still didn't help.
I apologize if this question sounds disjointed as I am trying to overcome one obstacle at a time and do not want to overload one question with multiple issues. I can supply my ERD if it will make things easier and I have it normalized to at least 2NF.

How can I save user settings on a per user basis?

I'm working on a program that needs a feature that has similar functionality as a contact list. I need to have user settings, but I don't know how, if it's even possible, to create application settings in code.
I would like to be able to add as many new "contact" settings as needed, so I figured if I couldn't create new settings, I should just have one setting that is a list, but that also doesn't seem to be possible. I've looked around on here and Google and can't find anything to fit my needs.
Requirements:
Store contact-like data such as phone numbers, email addresses, etc.
Be able to add as many of these contact settings as needed.
Everything in one executable file.
Edit: So there's the object data type, which seems to fit my needs. Is there a reason this wasn't an answer to any of the very similar questions to mine? It seems to be perfect..
Edit: Nevermind, seems to be compiler errors when trying to access a property of my object because it doesn't have that property until it's an instance of my own objects...
With JayP. Sql Server Compact might also be a possibility, it creates a local 'mini' database, without the need of a sql server installation.
While it is pedantic, I'm not sure a contact list should really be considered as 'settings'. It's really data. As such, it might be better to store this data in an XML file or similar.
Let me add my 2 coins. The data the #Walkerneo is talking about is not "settings" data. It's real data that should be considered in other way. I would suggest to separate them into 2 parts: real data and real settings.
The best place for real data is DB. It may be Firebird or MS SQL Compact or something else.
As for settings the Registry is a good place. At least Qt that is cross platform language uses this approach for Win apps
.

Non-Volatile object in C#

I want to be able to maintain a count and a last accessed date across application loads for a web service polling application. I'm not too sure what the best way to do this is. I dont like the idea of storing that data in a database as I would have to create one specifically for the purpose. What other options do I have and are there any particularly nice ways of keeping application state between subsequent runs of the app?
Persisting data eh? I suggest a database or file.
File solutions you can just XML serialize to a file and load it again when the app starts.
If the data is shared or might ever grow, then a database is probably the best solution. You can find one that fits your need among the many free projects if you wish:
couchdb
mysql
postgres
mangodb
membase
sqlite
etc
You could roll your own solution that doesn't involve a database, but most likely there is one that fits your needs and learning it would be useful beyond just the project at hand.
Don't be afraid to make a 'configuration' style table for your website, that simply has only a few rows and let's you store runtime information as needed.
Perfectly fine.

Automatically log changes made to records in database

I'm wondering what the best way to implement this would be.
Basically our project has a requirement that any change made to records in the database should be logged. I already have it completed in C# using Reflection and Generics but I'm 100% sure that I used the best method.
Is there a way to do this from inside the SQL database?
The big key is that the way our project works, the ObjectContext is disconnected, so we couldn't use the built in Change Tracking and had to do our own compares against previous Log items.
If you're using SQL Server 2008 or higher, you can implement either change tracking or change data capture directly on the database. Note that the latter is only available in the Enterprise edition engine. There are pros and cons to each method. You'll have to review each solution for yourself as there isn't enough requirement information to go on in the question.
If you're using SQL Server 2005 or below, you'll have to resort to a trigger-based solution, as suggested by the other answers.
You want to look at database triggers.
depending on the complexity of your datamodel you could setup on update/insert/delete triggers on the relevant tables - these triggers could log whatever is needed (old/new values, User, timestamp etc.)... see http://msdn.microsoft.com/de-de/library/ms189799.aspx
Look at my blog to see how you can track data changes without database scheme modification:
part1,part2
For your project requirement, SQL trigger is the better solution than the current C# reflection. Becaz triggers provides a way for the database management system to actively control, monitor, and manage a group of tables whenever an insert, update, or delete operation is performed. More over, the requirement is full filled at DataBase layer itself and so hosted as the single solution for various front end applications.

Data-Driven Websites for Very Small Businesses

I have a client who has a product-based website with hundreds of static product pages that are generated by Microsoft Access reports and pushed up to the ISP via FTP (it is an old design). We are thinking about getting a little more sophisticated and creating a data-driven website, probably using ASP.NET MVC.
Here's my question. Since this is a very small business (a handful of employees), I'd like to avoid enterprise patterns like web services if I can. How does one push updated product information to the website, batch-style? In a SQL Server environment, you can't just push up a new copy of the database, can you?
Clarification: The client already has a system at his facility where he keeps all of his product information and specifications. I would like to refresh the database at the ISP with this information.
You don't mention what exactly the data source is, but the implication is that it's not already in SQL Server. If that's the case, have a look at SSIS.
If the source data is in SQL Server, then I think you'd want to be looking at either transactional replication or log shipping to sync the two databases.
If you are modernizing, and it is a handful of employees, why would you push the product info out batch style?
I don't know exactly what you mean by "data driven", but why not allow the ASP.NET app to query the SQL Server product catalog database directly? Why generate static pages at all?
UPDATE: ok, I see, the real question is, how to update the SQL database running at the ISP.
You create an admin panel so the client can edit the data directly on the server. It is perfectly reasonable to have the client keep all their records on the server as long as the server is backed up nightly. Many cloud and virtual services offer easy ways to do replicated backups.
The additional benefit of this model is that more than one user can be adding or updating records at a time, making the workforce a lot more scalable. Likewise, the users can log in from anywhere they have a web browser to add new records, fix mistakes made in old records, etc.
EDIT: This approach assumes you can convince the client to abandon their current data entry system in favor of a centralized web-based management panel. Even if this isn't the case, the SQL database can be hosted on the server and the client's application could be made to talk to that so you're only ever using one database. From the sounds of it, it's a set of Access forms and macros which you should have source access to.
Assuming that there is no way to sync the data directly between your legacy system DB (is it in Access, or is Access just running the reports) and the SQL Server DB on the website (I'm not aware of any):
The problem with "pushing" the data directly into the SQL server will be that "old" (already in the DB) records won't be updated, but instead removed and then recreated. This is a big problem with foreign keys. Plus, I really don't like the idea of giving the client any access to the db at all.
So considering that, I find that the best is to write a relatively simple page that takes an uploaded file and updates the database. The file will likely be CSV, possibly XML. After a few iterations of writing these pages over the years, here's what I've come up with:
Show file upload box.
On next page load, save file to temp location
Loop through each line (element in XML) and validate all the data. Foreign keys, especially, but also business validations. You can also validate that the header row exists, etc. Don't update the database.
3a. If invalid data exists, save an error message to an array
At the end of the looping, show the view.
4a. If there were errors, show the list of error messages and tell them to re-upload the file.
4b. If there were no errors, create a link that has the file location from #2 and a confirmation flag
After the file location and confirm flag have been submitted run the loop in #3 again, but there's an if (confirmed) {} statement that actually makes the updates to the db.
EDIT: I saw your other post. One of the assumptions I made is that the databases won't be the same. ie, the legacy app will have a table or two. Maybe just products. But the new app will have orders, products, categories, etc, etc. This will complicate "just uploading the file".
Why do you need to push anything?
You just need to create a product management portion of the webpage and a secondly a public facing portion of the webpage. Both portions would touch the same SqlServer database.
.Net has the ability to monitor a database and check for updates. then you can run a query to [push] the data elsewhere.
or use sql to push the data with a trigger on the table(s) in question.
Is this what you were looking for?
You can try Dynamic Data Web Application.
You should have a service that regularly updates the data in the target DB. It will probably run on your source data machine (where the Access-DB is)
The service can use SSIS or ADO.NET to write the data. You can do this over the web, because you have access via TCP/IP to the server I assume.
Please check when the updates are done and how long it takes. If you can do the updates during the night you are fine. If not you should check, if you can still access the web during the import. That is sometimes not the case.
Use wget to push the new data file to the mvc app and once the data is received by the action, the mvc app invokes the processing/importing of the data (maybe in a worker process if you dont want long requests).

Categories