I have seen this question asked previously but can not find a clear explanation of what is/isn't possible and what workarounds migth be available.
I have an existing C# application that uses SQL CE to store local information. This database is only accessed by a single application and is stored in the user's appdata folder.
Some environments have the appdata folder redirected to a network share which causes SQL CE to throw an exception: "Internal error: Cannot open the shared memory region."
I have read that SQL CE 3.5 SP2 is supposed to allow connections to network shares again, and that SP1 does not, however I have not been able to get it to work. Has anybody had any success getting any version of SQL CE to work over a network share? And if so, what version/code did you use to get it to work?
I have tried using mode=Exclusive in the connection string with no luck.
Or alternatively, has anybody found a different workaround? The data needs to be stored in the user's profile as it is specific per user and should not be accessible by any other user on the system.
I updated the application to use SQL Express with local user instances which worked, but it created too many deployment issues for our customers. I ended up having to write a layer to use Access MDBs while we look at different database options.
My suggestion for writing desktop applications is DO NOT use SQL express or SQL CE for local storage.
I've used SQL CE 3.5 successfully on a networked drive with instances of an application running simultaneously on two networked computers. I was able to update records in the database from both locations.
I'm not sure what would happen if two users accessed the same record at the same time, however this is unlikely in my situation. Just include the database location in the connection string.
Store the data in a folder that is not redirected.
SQL Compact is a single-user, in-process database engine.
Have you tried to put sqlce DB on a shared folder and set its datasource where it is located?
Something like:
"Data Source=\\MySharedfolder\\DB.sdf;Persist Security Info=False;"
Related
In my application I need to use a local database (the application I'm creating works with everything locally). I had one database that worked really bad, because sometimes it saved the data and other times don't. And if I published the program I couldn't find the database file.
But I am having some trouble to know where to place the database. I have created one in E:\PAP\Trabalhos\Trabalhos\database.mdf and other in E:\PAP\Trabalhos\Trabalhos\bin\Debug\database.mdf, but in any of those paths the database is recreated/goes back to the previous state, when I try to start the program.
In my connection string I have this:
Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|database.mdf; Integrated Security=True
and that points to the file ...\bin\debug\database.mdf
I want to be able to access the database in any computer I use the program and be able to actually save data.
Where is the recommended path to place the database file and be able to access it independent of the computer I am using?
Should I use Windows authentication or SQL Server authentication?
tl/dr: Database doesn't save data and I want to be able to access it in any computer without any extra steps.
You can't use "(LocalDB)\" and access it from any computer. LocalDB is by design accessible only from the applications running on the same computer (it is an embedded database).
To access database over the network you need to install instance of SQL Server, like full SQL Server Express instance or use some cloud service like AWS or Azure.
I need your help to answer a question.
I coded a basic c# portable exe application that uses an Access Database on a server computer. On the network there are some client computers that runs this application and retrieve and store data via this database placed on the server computer in a shared folder. Every client coputer can access my database with this connection string:
#"Provider=Microsoft.ACE.OLEDB.12.0;Data Source =\\ANKFILESERVER1\aractakip\DatabaseAd.accdb
So far, there has been no problem. But as known, Access (Oledb) database has a limited capacity to save datas and since i'm worrying that someone change or delete my database files -authenticated for everyone- i decieded to use another database platform like postgresql.
My question is, if i install postgresql on the server computer and migrate my database tables, Are every client computers needed to install postgresql to access my database tables? If yes, what should be my connection string?
Thanks in advance.
You will need a client driver - like psqlODBC - installed on each computer that connects to PostgreSQL via MS Access, yes.
You can install psqlODBC separately, or using the main PostgreSQL installer. The separate psqlODBC-only installer is an msi that can be deployed over Active Directory, making management easier.
The connection options are covered in the psqlODBC documentation.
Microsoft Access is really written for the Microsoft JET / OLEDB engine, and to communicate with Microsoft SQL Server. It works with PostgreSQL, but it doesn't fully "understand" all PostgreSQL's features. It also does some things in totally non-SQL-standard ways that work on MS SQL but do not work on PostgreSQL. So it can be awkward to use MS Access with PostgreSQL due to things like Access not really supporting SEQUENCEs properly. Note, though, that I haven't used Access since Office 2008, so things may have improved.
here is the problem I am facing now. I have created an application that uses local database (this was created by Add -> New Item -> Local Database. Afterwards I have added tables under this .sdf database.
Then I have connected to this database using Add -> New Item -> ADO.NET Entity Data Model.
Everything works like a charm, unless I was asked to move this database to a place, where multiple people could access this database and work with it.
Therefore, as I have no previous experience with databases, I have treated this .sdf file as any other file (let's say Excel workbook) and I thought that I could simply take already existing database, copy it on server computer (e.g. \Server001\Database\Database1.sdf) and simply change connection string under app.config.
However the problem is that this does not work. As I didn't know how to change connection string, I created new application, where I have tried to connect to this database located on a server computer; however I received the following error:
SQL Server Compact does not support opening database files on a network share.
I already have fully functioning program, but I have no idea how to make it work with multiple users. I have tied to google for solution, but all I could find is how to create local database, not how to make it accessible by placing it in server computer.
Could you guys please help me? If you need more details, please let me know!
P.S. This is WPF application, .NET 4.5, created using Visual Studio 2012 Professional.
Thank you!
The error message pretty much sums up the problem: SQL Server Compact does not support opening database files on a network share.
SQL Server Compact (aka "local database") is to be consumed by a local application; even if it was a web app serving many requests, the application itself is local.
If you want to have multiple remote connections (i.e. centralized DB, distributed app), you should look at using an instance of SQL Server (any SKU would probably work, even SQL Server Express). Those will use MDF files instead of SDF files, so you might want to refer to Convert .sdf database to .mdf database. You'll probably also need to set up a user identity for your connection string, so check out this link on CREATE USER and Difference between a User and a Login in SQL Server to understand how that can be configured.
I have developed a winform application in C#.net and using SQL Server 2008.
My application inserts and updates values into database.
Is it possible to install the application on a another system which doesn't have sql server on it?
Imagine using sql azure. Cloud based sql server. The database is never on the same physically computer. It's all down to the connection string.
With an on premise database you need to make sure the database allows external connections, maybe opening up firewall etc. then make sure the connection string is set correctly on the application to talk to external database.
You can even configure to change the connection string as required pointing at different databases depending on the individual requirements.
Scott
Yes, you can. You can access the DB remotely by referring remote DB server in connection string.
It is possible, if you are looking to run the application on machine that is running on the same Domain as the SQL Server and has privileges to the SQL Server.
I have built a SQL database program that holds part numbers and details about them. Right now the program works locally on my machine. However, what I need to do is have the program access the database on a network drive (eg. the L:\ drive). This way, a user can have their own copy of the program, but all the data that is sent and received is done to that common networked database. I have been playing around and also searching online, but cannot seem to find anything, and I am a database beginner. Any help would be much appreciated. Thanks.
What you want to do is install a sql server instance somewhere on your network. Then use a connection string rather than a drive location to access the data.
This is the standard way to share data across applications.
THe problem with this approach is locking and multiuser support to put it simply. You will run into users contending for access to the file . You need a DB server ( SQL Server , Sql Server Express, MySQL , etc etc) to handle this problem for you . The DB server can running on that network server .