I want to develop a multiuser supporting accounting management application in C#.
I want to use Linq To SQL classes. LINQ to SQL only supports SQL Server/Compact. However is it possible the SQLite people have written their own LINQ provider given the name of the assembly.
I have to use DBMS that is FREE. Which DBMS do you suggest to me?
LIN2SQL = SQL Server. Second class badly written O/R mapper compared to the real contendors (like NHibernate).
LINQ2SQL != LINQ. LINQ is the query integration into the langauge, and supported by pretty much a lot of O/R mappers out there, and some databases.
I have to use Db that is FREE.
Free like for free? What is against sql server? Express edition - 0 USD. And the 4gb "database size limit" does not stop you from writing accounting systems. THat is a LOT of space for accounting data. For many years of accounting data.
If you want to use Linq-to-SQL (which I think is an excellent choice) you have to use some variant of MSSQL. Both Sql Server Compact and Sql Server Express are free to use. If you have a multiuser scenario you will have to go for Sql Server Express as Sql Server Compact doesn't allow multiple simultaneous access.
There are various experimental linq to sql and linq to entity framework providers for other databases(like mysql and postgres) - in my experience they are so immature it is not worth using for anything serious.
For now, I'd suggest you'd look for something else if you cannot use SQL server.
Try the following link:
http://sqlite.phxsoftware.com/
Note that Linq2SQL is not compatible with SQLite, however the link points to an Entity Framework provider for SQLite. EF is kind of like Linq2SQL on steroids. SQLite is very lightweight, so the EF implementation above should work nicely for your needs.
Related
So far I have been using SQL Server Express on my desktop application even though usually the server is only used by that single application, by the single user, on the same single machine. This always seemed a bit silly to me since the full-on server is rather heavy.
Then I found out that there is something called SQL Server Compact. Thing is, my application is already rather large. So my question is that if I wanted to change to SQL Server Compact, what kind of changes to my code are we talking about (using C#)?
Mainly I'm wondering if I can access the Compact -version in the same manner as I can access the Express one, which is using ADO.NET and pointing it towards localhost\sqlexpress. So would it be possible to create another instance with the Compact and just point my application to that, or is it used in a completely different manner?
For a standalone desktop product it is certainly a lightweight option to consider over SQL Express.
However there are differences between the two to be aware of other than just connection strings. For example SQL CE does not support stored procedures, user-defined functions, or triggers. Additionally it does not support the full range of datatypes that Express supports. On a technical level it also runs in process with your application.
Another consideration is that while SSMS will work with SQL CE databases, it's not as fully featured as it is with SQL Express. There are however a whole raft of good tools out there for filling these gaps. Take a look at Erik Jensen's blog for a good overview.
Everything SQL Server Compact
Also check out his tool for migrating SQL Express databases to SQL Compact:
How to Migrate/Downsize a SQL Server database to SQL Server Compact 4.0 (and 3.5)
Finally take a look at this SO question for more background between the two products:
What are the limitations to SQL Server Compact? (Or - how does one choose a database to use on MS platforms?)
I worked recently with it, by the way the things I know about using them is that SQL Express has a server to connect to, and, Compact is a sdf file, so the first thing you will have to change is the connection string to it.
After this change, there are no more heavy changes to be done, I remember, compact has almost all the instructions of the express server available, so, it could not be much problem.
Take a look at Microsoft documentation for more information, or at Wikipedia.
See you.
I would vote against SQL CE:
It has no views, which might be an issue when migrating.
We recently did something similar which you described and had tremendous performance impacts when switching from SQL Server Express to SQL Server Compact Edition.
My recommendations would be:
Use SQLite (which we did for the project I mentioned - it was much more performant than SQL CE in our case) -or-
Use VistaDB (which I did in other projects; not as performant as SQL Server Express, but still sufficient)
Both databases can be XCOPY deployed, just like SQL Server Compact Edition.
SQL CE has the same size limitation as Express, so you should be good.
As far as moving between the two, I found this for moving between express databases and compact 3.5 databases. Then I think you'll only have to change your connection strings (instead of pointing at a host/instance, you point at the converted file). There are different features between the two, though, so you might have to change your schema in the original database for the conversion to go smoothly.
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 think we may have trouble with our existing project. For some reasons we have to switch from SQL Server to Sybase SQL Anywhere 11. now we trying to find a way continue use our existing LINQ code.
We wish we can still use L2S? If cannot, we wish we can use L2E, then we have to change to ADO.
how to generate dbml file from Sybase Anywhere 11? after that can we use sqlmetal to generate .cs files?
Linq to SQL only supports MS SQL Server. You might consider switching to Entity Framework if this is an option and if there is a provider fro Sybase SQL Anyware.
As far as I know there are also no plans to extend the Linq to SQL support to other databases, especially as MS pushes EF as the future database technology.
I have a simple app written using SQL Server, Entity Framework, C# and WCF. When I wanted to share this app with my friends, I realised they didn't use SQL Server on their machine. I could go for SQL Server Express edition, as the usage of my app is personal and non-commercial.
I found MySQL as a popular alternative to SQL Server.
1) Would I be required to update my entities when moving to MySQL?
2) Should I anticipate code changes in my BL layer due to change in entities layer? (I am wondering whether entities was built for SQL Server)
Are there any databases similar to MS Access that is lightweight compared to MySQL?
Are there any databases that need not be installed but can be copied around like MS Access?
Appreciate your response!
Sounds like you want SQLite.
SQLite is a software library that
implements a self-contained,
serverless, zero-configuration,
transactional SQL database engine.
Very easy to deploy. Also, check out System.Data.SQLite.
According to the System.Data.SQLite page ...
Supports nearly all the entity
framework functionality that Sql
Server supports, and passes 99% of the
tests in MS's EFQuerySamples demo
application.
You should be good. :)
Im not sure how your BLL looks like and i have no experience with entity framework, but ive experienced multiple times that linq-to-sql works much better with sql-server as with any other database.
So unless you have a good reason not to use sql express, i'd advice to stick to sql express.
After all, you should always install something when deploying (unless you use xml as storage, which is quite well possible with linq-to-xml).
VistaDB Express Edition is also free for non-commercial usage and integrates good into .NET and VS. afaik it also works on a single local data file thus requires no specific installation on your friends' computers.
Otherwise I recommend using PostgreSQL over MySql since it is more standards compliant and has a nicer license.
I think what you're after is just a change in providers. What you need to use MySQL is the .Net Connector which supports most everything simple. It's not very mature yet so something very complex you may have issues on, but it should do most of what you want through Entity Framework.
With Entity Framework yes you can do updates, it's LINQ-to-SQL that doesn't update against any other databases (unless you use a third party provider like DotConnect)
SQLite is one alternative, but since multiple threads against it can cause major issues with it's operation, so if you need a major data store I'd go SQLExpress or MySQL.
Yes, you could use MySql with EF but I don't know if it would require changes.... I wouldn't be surprised if it does though. At the very least your physical DB would have to be ported / converted to MySql and that will take time.
I would assume that if you need to install a DB on your friends Pc's why not stick with SQL Express since you already developed in SQL Server on your box. Should be less issues with this than migrating to MySql.
I'd also vote for VistaDB 3 as it's so easy to deploy.
Would someone explain how to get LINQ working with Sqlite.
Here you have an SQL Linq provider for SQLite, and some other DBs
Joe Albahari's LINQPad now supports Sqlite: http://www.linqpad.net/Beta.aspx. The one LINQ tool to rule them all.
The link provided by CMS doesn't work anymore. I have used this one as it now seems to be baked into their SQL lite ADO .NET provider.
Unfortunately they still don't support the designer mode of VS for creating classes :(
Also be aware that SQL Server compact doesn't support the design mode for LINQ classes! However if you want to use the entity framework the designer does work for SQL lite and SQL Server compact :)
Yup there is a SqlLite Linq Provider as mentioned by CMS
Check out SQL server compact and it works well with Linq
There is another thread on SO which you should check
I would like to add that you can use Linq to Sql with SqlLite with a couple of stipulations:
You cannot use the Linq to Sql designer which means you have to hand roll your classes.
You have to be careful not to do certain operation which will result in Sql code which is not supported by SqlLite.
For example, you cannot use FirstOrDefault() in any of your Linq queries because it will result in something like:
select top 1 * from table where ...
Since SqlLite doesn't support the "top 1" syntax, you will gt a runtime Sql error.
Other than that, I have been using Linq to Sql with SqlLite with great success for basic CRUD operations.
You can use this: http://code.google.com/p/dblinq2007.
Although it looks like the project is still in Alpha stage, IMO it is actually very stable now. Of course if you have a huge project, it is better to consider using something else like MySQL or SQL Compact. I don't like SQL Server, because it is too bloated, and offers not many more functionalities over SQL Compact or MySQL
Check this provider:
SqlLite Linq Provider
Also you can consider using SQL Compact which has very good LINQ-to-SQL support.
On this time there is NO good tools to do this!
LINQ providers for SQLite all is in alpha stage (for example:dblinq2007). And it is very big risk to use it in commercial purpose! So maybe in future...
If you want ot use ADO.NET there is good ove: phxsoftware.