I am using SQLite local database in my C# application (WPF).
Should not you open the database connection once and load all the data in the beginning (instead of opening the connection everytime you need a bit of data from the database)?
My question is where should that data be stored in the application.
Should I create a static class which contains all the information in multi-dimensional arrays or multi-dimensional lists. Or is there a better way to store the information?
those are the most common tools for this task:
(by my order of recommendation)
http://en.wikipedia.org/wiki/NHibernate
http://en.wikipedia.org/wiki/ADO.NET_Entity_Framework
http://en.wikipedia.org/wiki/ADO.NET
Your question cannot be properly answered without knowing your business logic.
However, I can tell you that no most applications do NOT load the entire database into objects but rather queries the data when the data is needed.
For the other part of your question, why dont you create a ADO.Net data model? There are templates available if you are using vs 2010, just type model in the search box after opening new project.
Take a look at datasets and the dataset designer tool of visual studio.
If You use this approach, You can benefit from nice features, like serializing tghe data to xml and so on.,
Yes your initial solution is ok,In order to prevent traffic between your App and DB you should save your data in memory,such as propery that you have mentioned before but you could benefit of Caching advantages.
if your are using .Net framework 4.0 ,you can utilize System.Runtime.Caching ,otherwise, you should be familiar with Enterprise application block 5.0 or lower.
Related Post
System.Runtime.Caching-MSDN
Related
i developed C# application for windows the back end is mysql database but the problem is, if i want to run it in different computer it requires mysql server software or other wise it cant open the data base. is there any way to add plugins to the s C# application or adding open source software to my installation package to run the database file. please note i'm new to C# this is for education purpose sorry for if my questions asking method is not professional.
Front end : visual studio 2013
Back End : Mysql server 2008
I dont know if i got your question right but i assume it a general Data Access Layer strategy question.
If you "bind" your application with mySQL or any other db then that's it.
Depending on the size of the application you could use open source db like SQLite It is a one file db that can be stored with your application.
If you really want to be able to use your software with many underlying DBs then you have alot of job.
THIS question in SO debates that maybe it is not a good idea or at least it is a partially good idea. Partially means that you could abstract basic db behavior to be db independent but you will not get rid off the dependencies 100%
Another good approach would be to use an ORM. Either a micro ORM like dapper or afull ORM like Nhibernate
ORMs let you do just that. You can use an OleDb provider and have access to many underlying sources at a cost of course of not using 100% the native capabilities of the DB....
My WinForms C#/.NET application requires a table/grid control to display records to the end user. The records will be simple, containing only two fields, a string and a date/time field. I need to persist the data and I am wondering what the most efficient control and storage back-end is to use. The data is non-critical (i.e. - not health or financial records, or anything sensitive requiring extensive safety or any encryption).
One solution I have found so far is the DataGrid control in conjunction with SQL Server Compact Edition. I learned about this solution from this tutorial:
http://www.dotnetperls.com/datagridview-tutorial
It seems though that this may be overkill for my application. In addition, I am worried about the complexities of installing SQL Server CE, especially when it comes to admin vs. user account privilege issues during installation:
http://msdn.microsoft.com/en-us/library/aa983326(v=vs.80).aspx
Is there a table or grid control with built-in file load/save capabilities that uses a simple disk file as the storage method, perhaps a comma delimited ASCII file? I'd like something that I can still use SQL (via LINQ) to interface with. also, I am hoping that this can be done transparently. That is, if I want to upgrade to an SQL database engine solution later, the code from my end that interfaces with the data would not change (except perhaps for the database open/create code of course).
Or am I better off simply biting the bullet and going with SQL Server CE or perhaps SQLite:
Good embedded database solution (like SQLite) for .Net
If you have any caveats or anecdotes regarding installation issues and ease of use, they would be appreciated.
In my projects, we use Object datasources. Grid's can be bound to collections of objects just as easily as they can dataTables. You can store/restore the data using a simple serialization engine (XmlSerializer is rather easy to implement). Make a basic object, use List or BindingList as the dataset, and serialize/de-serialize it in the backEnd when you need it.
List and BindingList both support Linq queries.
Adding database save later is as simple as writing the code that saves the object to the database, in place of the serialization code, no change to the front end at all.
As far as a "Correct" solution is concerned...there are so many different ways to do it that it boils down to personal preference, and possibly actual requirements and expected future development. I find it easier to code using objects because the data manipulation is easier, but if you are going for straight record entry, no data manipulation required, going direct to a database is easier. It just depends on the data and what you plan on doing with it.
I strongly recommend you to use an embedded database, because it will be easier to go to a full database in a near future. SQL Server CE is a good option, and if you want to go big you can simply go to a full SQL Server Database with minimal changes in your code, the only downside of SQL Server CE is that you need to install it and it requires the .NET Framework 4, aside from that I don't see a big problem with it.
I've made a local database for a C# project:
I know basic SQL commands, but haven't worked with databases in C#.
What I'd like to know specifically is:
How to read from the database (query)
How to add and update rows
The database only consists of 3 tables, so I don't think anything fancy is needed.
First, you should learn a bit about various technologies and APIs for connecting with a database.
The more traditional method is ADO.NET, which allows you to define connections and execute SQL queries or stored procedures very easily. I recommend digging up a basic tutorial on ADO.NET using Google, which may differ depending on what type of project you're creating (web app, console, WinForms, etc).
Now days, ORMs are becoming increasingly popular. They allow you to define your object model in code (such as every database table would be a class, and columns would be properties on that class) and bind to an existing database. To add a new row to a table, you'd just create an instance of a class and call a "Save" method when you're done.
The .NET framework has LINQ to SQL and the Entity Framework for this sort of pattern, both of which have plenty of tutorials online. An open source project I really like is Castle Active Record, which is built on top of NHibernate. It makes defining ORMs quite easy.
If you have specific questions about any of the above, don't hesitate to post a new question with more specific inquiries. Good luck!
Update:
I thought I'd also put in one last reference as it seems you might be interested in working with local database stores rather than building a client/server app. SQLite allows you to interact with local stores on the file system through SQL code. There's also a .NET binding maintained by the SQLite guys (which would in theory allow you to work with the other platforms I mentioned): http://system.data.sqlite.org/index.html/doc/trunk/www/index.wiki
You can use SQLCE.
This blog will give you a good start.
http://weblogs.asp.net/scottgu/archive/2011/01/11/vs-2010-sp1-and-sql-ce.aspx
Here is a small tutorial that should be helpful to you.
You can make use of the SqlDataReader to read data
and the SqlCommand to Insert Update Delete rows from your tables.
http://www.dotnetperls.com/sqlclient
You could use it by adding following to your Startup.cs
services.AddDbContext<DemoDbContext>(options => options.UseSqlite("Filename=data.db"));
I am working on a personal project as a way of learning more about C# and .NET, specifically creating an application that utilises a database (MS SQL Server 2008 in my case). Whilst I appreciate there isn't always a definitive "right" way of doing things, given the choice between using an old technology/idea or a new one, I would rather use the new one. For example, one of my aims for this project is to learn, or at least familiarise myself with, WPF rather than using WinForms as I have done in the past.
On that basis, I've been muddling around without a great deal of direction with regards to saving data to my database and retrieving it. So far I've managed to get both those working using TableAdapters but I feel like they are the "old" way of working (my basis for this is that they are listed under Visual Studio 2005 on MSDN). Firstly, am I correct in this assumption? If so, what are the newer methods of saving and retrieving data from a database? I would be grateful of any pros and cons each method offers.
I've Googled and searched MSDN extensively but I don't feel like I am using the correct search terms as I have only succeeded in confusing myself.
I have .NET 3.5, Visual Studio 2008 and Microsoft SQL Server 2008 at my disposal.
Any guidance would be much appreciated.
I would agree that TableAdapters, DataSets, DataTables, etc. are the "old" way of doing things.
The "new" way would be Linq-to-SQL, Entity Framework or NHibernate.
Personally, I like to use a combination of Linq-to-SQL along with plain old DBConnections, DataReaders and DTO's where needed.
If you would like a newer way of doing Database access in .NET, I would recommend looking into LINQ to SQL or the Entity Framework.
There are many many many different ways to retrieve data from SQL Server 2008 using .Net.
Table Adapters are not a bad way; they are core to the .Net Framework, easy to get started with and reasonably powerful, although they do not perform quite as well as other options and often require more memory.
Basically Table adapters are good if your data is structured the way you want to view it. If you want to view data in a different way to it is stored you can do this with a table adapter but you loose the ability to write back changes to the database, this is OK if you are just generating a report.
If you want to view and change the data and the data is not in the structure you want to view it you need entity framework so you can query the data to get it into a different format and still have the ability to write any changes back. This is what the call the data from the server the MV to the display the VM
I'm very new to C#, so please forgive me if I've overlooked something here. I've created a database using Visual Studio (add new item > service-based database) called LoadForecast.mdf. I then created a table called ForecastsDB and added some fields.
My main question is this: I've created a console application with the intention of writing some data to the newly created database. I've added LoadForecast.mdf as a data source for my program, but is there anything else I should do? I saw an example where the next step was adding a "data diagram", but this was for a visual application, not a console application. Do I still need to diagram the database for my console app? I just want to be able to write new records out to my database table and wasn't sure if there were any other things I needed to do for the VS environment to be "aware" of my database. Thanks for any advise!
Well, it depends on what data access technology you want to use. You can use straight SqlClient, you can use untyped data sets, you can use strongly typed data sets, you can use LINQ to SQL, you can use Entity Framework.
If you're not sure, then probably the most fun would be LINQ to SQL, so I recommend you follow a tutorial first and then come back to your app. Eg. ScottGu's LINQ to SQL (Part 4 - Updating our Database), or MSDN's How to: Insert Rows Into the Database.
There are also video guides, like VS2008 Training Kit: Using LINQ with Relational Data or MSDN Webcast: Using LINQ with Relational Data (Level 100).