How do i create a db file in C#? a friend told me it was in the toolbox and not to use sqlite. I dont see anything that could be it, nor what it is called. google didnt help:(
Could it be...
SQL Server Compact Edition – A lightweight, in-process database engine designed to run on devices and desktops and is geared toward local data storage. Compact Edition includes a subset of SQL Server 2005 data types and shares common elements of the Transact-SQL (T-SQL) language with the data service engines.
There is no file-based database provider built in to c# or the .NET Framework. There are of course pre-existing connectors for using SQL Server (which includes SQL Express), but if you need a fully functional RDBMS that is file-based, you need to use something like SQLite or Firebird (also a fan of VistaDB, not free or open source but VERY solid and pretty affordable).
On the Add New Item menu: "Service-based Database" or "Sql Server Database" if it is an asp.net application. I am sure your friend meant it as "create a sql express db file in Visual Studio".
That said, if you wanted to fill an empty database, with tables that correspond to a c# model, you could create a linq2sql model, and use its CreateDatabase to do that for you :)
You might want to check this http://quickstarts.asp.net/QuickStartv20/aspnet/doc/data/vwd.aspx (visual web developer link, but it applies).
For a full/in-depth explanation of how SQL express can be used with a semi file based approach check and its limitations:
http://www.databasejournal.com/features/mssql/article.php/3704171/SQL-Server-2005-Express-Edition---Part-8---XCopy-Deployment.htm
Perhaps you might try Microsoft LocalDB.
It is file based but uses a low level SQLExpress Installation to host it.
If you are using Visual Studio or Web Developer Express, there are indeed ways to easily create a MS SQLExpress database. Just go to Add New Item... and it should be one of the available file types.
Keep in mind you have to have installed either Microsoft SQL Express Edition (free, as in beer!) or Microsoft SQL (very un-free!, in all senses). If you haven't done this, you don't get the option of creating a database file so easily. If you have got it yet, you can get it here.
As other answerers have mentioned, strictly speaking this is NOT a C# feature. MS SQL and it's derivatives, are database applications, much like Oracle, MySQL, or PostgreSQL. It's just that Microsoft Visual Studio makes using the Microsoft database product very easy by default. Differentiating between C#, Visual Studio, and any database programs will probably get you better answers, faster, no matter where you ask. :)
Every database has a file system in some binary format more than likely custom and uses a cache to control the flow of the database(s) lifetime.
If you create a database system, you will need some type of cache because you only want to read from the file if the cache has already released it.
If you have 1000 clients tapping into the same db, you certainly don't want to read/write to the file for each client request, so you want to manage a queue of clients and run it against the cache so that the cache knows not to release the db after its time span for lifetime is reached put to rather update the time span, therefore, not having to reload the file, if disposed and queued again, until the queue referencing the db object is empty.
Creating a well designed cache it used by all rdbms's so that duplicate objects are not created and files are not reloaded if not need be.
You can use
FileDB - A C# database to store files
http://filedb.codeplex.com
There is a MVC Example in the source that allows you to upload files and also has drag and drop support.
It then saves it into just one file in a location that you specified.
Like this:
private string pathDB = #"C:\CMS-MVC\Parts\FileManager\filedb-19055\trunk\MvcTest\Data\MvcData.dat";
That one file will store all of your files in that one "container".
You are mistaken. Databases are not developed in C#. Databases are built using a database system such as Oracle, MS SQL Server, MySQL, and numerous others.
Once you build a database using one of the above providers, you can then perform actions on the database using your programming language of choice (in your case C#) to get data out of and put data into it.
Related
I need your help to manage an issue with my C# program. I wrote a GUI that allows the user to manage a lot of data stored in a SQL Server database. Everything works fine but I want to be sure that the application works even when the server is down (for a generic issue).
My plan is to have a local database (e.g. *.mdf database used in Visual Studio) and update it every time the GUI is able to connect to the online SQL Server database.
What do you think? Is there something similar to a procedure or do I need to do it manually (create a .mdf file, check the online version, write the changes etc.)?
Apart from the comments noting that this may not be a good idea (which I agree):
Most of the work must be done manually. If you have a DB model within your application (like when using entity framework) it could be that it can create the DB structure in the local file. Most of your data will need timestamps to determine when they were changed the last time.
The Microsoft Sync Framework might utilize you but I have not used it personally. Look here http://msdn.microsoft.com/en-us/library/bb902854(v=sql.110).aspx
I am looking for a solution in which several applications on the same machine access one and the same database. Generally the operations are just reads thus I am not interested in having to provide concurrent write access as well.
I checked into SQL Server Express, SQL Server LocalDb, SQL CE, SQLite, MySQL and am not convinced which one is the best solution. I read that SQL CE allows concurrent read access but SQL Server LocalDb does not, which I find very odd given LocalDb is hyped by MS as a version that is very similar in functionality to the SQL Server family and which is supposed to make it easy to later on scale out.
I like to manage 5-10 tables each of which holds less than 5000 rows, so really lightweight content.
I am looking for a solution that meets the following requirements:
Concurrent read access by several applications on the same machine
Should be somewhat lightweight. I intend to move all applications within a solution to a different machine later and do not want to have to install a 200mb full blown SQL Server Ex#ress version if possible.
Should play well with VS2012 express (sqlite and mysql are highly unsupported in that regards, either not supporting EF5 or they do not show up in the server explorer.
Should be an SQL solution in order to manually update database tables within a management console such as Workbench or Management Studio or other third party app.
Should work somewhat with EF or other ORM solution. I want to be able to create an entity class and create a database from that or update tables using class objects. Also I want to populate class object collections from table rows without having to go through SQL code.
I target C# in .Net 4.5 and I guess it boils down to the question whether SQL CE is up to the task to allow concurrent reads and how I can load CE data tables and edit and visualize the content in some sort of management console. Also does SQL CE play well with EF5? Any better suggestions?
Since you're asking for an opinion, SQLite is my answer.
We are aware of no other embedded SQL database engine that supports as
much concurrency as SQLite. SQLite allows multiple processes to have
the database file open at once, and for multiple processes to read the
database at once. When any process wants to write, it must lock the
entire database file for the duration of its update. But that normally
only takes a few milliseconds. Other processes just wait on the writer
to finish then continue about their business. Other embedded SQL
database engines typically only allow a single process to connect to
the database at once.
Entity Framework on SQLite
System.Data.SQLite
Setups for 32-bit Windows (.NET Framework 4.5)
This setup package is capable of installing the design-time components for Visual Studio 2012.
SQL CE Works with EF5 and VS 2012 Express, is very lightweight, supports multiple readers on the same machine, and can be managed in VS Pro+ combined with the SQL Server Compact Toolbox add-in (or standalone) (I am the author)
In my application programming experience, I have always worked with a SQL Server (or Access) database on the back end that stores application data. I'm now looking at some business requirements that work with data that would fit well in a relational database, but they require it to be stored in a single, portable, custom file that the application will create, and load from. I know it's a very common concept for an application to save off a single file or document that it can later load and continue to work on, but I'm not sure how to achieve this with complex data. Encrypting xml comes to mind, but that would be very slow to work with or potentially eat up a lot of memory if I had to load it all back into objects first. What are some options?
I recommend you use a SQLLite or Firebird embedded database. There are other options as well. They support single-file usage and will give you a clear upgrade path for future versions of you schema (upgrade SQL scripts).
I did not understand how encryption plays into this.
When running in a .NET environment I think that SQL Server Compact is worth looking into. It is basically a mini SQL Server that doesn't have to be installed and configured as a service, but instead is an dll that you reference. You can use normal data access tools like linq-to-sql and entity framework.
SQLite comes to my mind. Its a single file based DB. Here is a link to convert SQL server databases to SQLite. Also check out Using SQLite in your C# Application
I'm making an application in C# (with Express Edition) for which I would like to add some SQL functionality so that the user can query a database. I don't care how or where I store the database. I can store it in a DataTable or a bi-dimensional array or any kind of file. But I want the user to be able to SQL-query it. Apparently this should be quite simple since the .net seems to be full of database libraries and stuff. I was thinking about downloading MySQL and see if I can connect it to my application. I guess if I want to distribute my application then the user would need to download MySQL as well, which is not a big deal but would be great if I can avoid it. Anyway, for now I would like to start working on my program ASAP, so whatever is the easiest way to do what I want, even if it's not distributable, (but if it is then that's even better), will be good. Thanks in advance.
There are embeddable databases. SQL Server Compact Edition and SQLite are common ones. You can execute queries against these just as you can MySQL or SQL Server.
SQLite (.NET)
SQL Server Compact
You can use most popular databases with .NET. SQL Server, Oracle, MySQL, etc. But you're gonna need drivers of each. So, I'd suggest using SQL Server Express Edition to you to get started.
Then you can easily use SqlConnection and SqlCommand classes to connect and execute queries.
You could use a dbml file in your project and link it to your sql database and then run a sql statement using Linq2SQL documented here
I would look at using and embedded database that you can distribute with your application. SQLite is a very good option. You can then use a free ADO.Net library like System.Data.SQLite for data access. It also provides design time support for Visual Studio.
You can use LINQ to Objects or LINQ to Datasets to run LINQ queries with no database whatsoever. You can't use a bi-dimensional array, but you can use a List<> of objects with properties as a LINQ context.
From your question it sounds like your application, like most applications, may need to store the data for later use: that's where a database will come in handy. .NET Datasets have built in support for persistence to an XML file if your data storage requirements are simple enough to use that. .NET also supports persistence for objects, but you may find that using a database is the simplest solution, especially if you require multi-user access and editing.
I am in the midst of writing a small program (more to experiment with vs 2010 than anything else)
Despite being an experiment it has some practical use for our local athletics club.
My thought was to access the DB (currently online) to download the current members and store locally on a laptop (this is a MS sql table, used to power the club's website).
Take the laptop to the event (yes there ARE places that don't have internet coverage), add members to that days race (also a row from a sql table (though no changes would be made to this), record results (new records in 3rd table)
Once home, showered and within internet access again, upload/edit the tables as per the race results/member changes etc.
So I was thinking I'd do something like write xml files locally with the data, including a field to indicate changes etc?
If anyone can point me in a direction I would appreciate it...hell if anyone could tell me if this has a name, I'd appreciate it.
Essentially what you need is, in addition to your remote data store, a local data store on your desktop. You could then write your code by hand to sync the data stores when you go offline / online, or you could use the Microsoft Sync framework to handle it for you.
I've personally used the Sync framework on a number of projects and once you get used to the conventions, it's pretty easy to use.
If a local storage format is what your after. SQLite is one option. You can copy your tables from the server to your local SQLite db.
You could also save your data to files, but XML is a horrible format for doing this. You'll probably want to use YAML or JSON instead.
You may want to take a look at SQL Server Compact -- it provides some decent capabilities with synchronizing back with the mothership SQL server.
If you're using MS SQL Server for production, and you only need to work offline on your personal computer, you could install MS SQL Server Express locally. The advantage here over using a different local datastore is that you can reuse your schema, stored procedures, etc. essentially only needing to change the connection string to your application (which you could run locally too through Visual Studio). You would have to write code to manually sync your online and offline db instances, but since it's a small application, it may be reasonable to just copy the entire database from production to local and then from local to production when you get home (assuming you're the only one updating the db, and wouldn't be potentially wiping out any new records entered in production while you were at the event).
Google Gears http://gears.google.com/ is intended if your app is a web app (which I didn't quite get what it is from your description)