I have developed this application for a store owner.I want to allow the owner to backup and restore database by using the application.the backup runs fine but the restore is causing an exception which says that - Operating system error 32( the process cannot access the file because it is being used by another process).Restore database is terminated abnormally.
using(var conn = new SqlConnection(ConnectionString))
{
using(SqlCommand cmd = conn.CreateCommand())
{
string datadirectory = Path.Combine(Environment.CurrentDirectory,#"Data");
string query = #"RESTORE DATABASE""{0}""FROM DISK= '{1}' WITH REPLACE";
string query = String.Format(query,backupfile,datadirectory + "\\Database.mdf");
conn.Open();
SqlCommand command = new SqlCommand(query,conn);
command.ExecuteNonQuery();
}
}
How can I solve this issue ? Thanks in advance.
You have to dispose of every SQLiteConnection, SQLiteCommand and SQLiteDataReader once you are done using it. The second command that you create isn't correctly being disposed off.
That aside, your code sample doesn't really make sense. You create a command that is never used. Then you create a second command that isn't properly disposed off.
Is it the restore-file that is blocking? Or is the database itself still running?
If it is the database that is being used, you can set the database in single-user-mode. Another option is taking the database temporarily offline and bring it online again. That should close all existing connections. Tip; with SSMS you can turn almost every command into an SQL script like the button to brink a database offline. Click on 'Script' and you get something like 'USE MASTER GO ALTER DATABASE [AdventureWorks] SET OFFLINE GO'.
wait, this is good news. it looks like the application is running, the db is online and live, so why do want to restore? backups are something you do daily/hourly... but restores you ONLY do if something goes wrong. of course you got an error. the db is live and sql service is using the files and it's good it didn't let you restore or else you would have lost a lot of data.
if all you want is to test the restore, then you need to shut down the sql service first.BUT, make sure you take a backup just before that so you restore the latest.
Related
I'm creating a backup monitoring application that I am going to write in Visual Studio using ASP.NET.
The way I would like this to work is backup emails being sent from the server that has a backup monitoring solution and are stored in a SQL database (SQL Server Express, MySQL) whatever would be best for something like this. I then plan to use this data to query and show statistics such as what servers have backed up successfully for each customer, and those that have failed. Also what servers have backed up successfully most and error trends such as not enough disk space etc.
Would this be possible and if so could someone point me in the right direction wither I should start trying to get information into a database first and foremost and how to achieve that or should I start by creating the application such as login, dashboard etc. I haven't got a strong programming background we covered some Visual Basic and ASP.NET in university and I was hoping to learn a lot from this project.
I was thinking of setting up a test environment with a server running a backup product and purposely making backups fail for testing and have access to the hardware/software resources working for an IT Consultancy / Support company.
Thanks in advance!
After some searching I came across this website which has a great piece of code that reads emails from an inbox such as Gmail and stores them in an SQL database.
protected void SaveEmails(object sender, EventArgs e)
{
for (int i = 0; i < this.Emails.Count; i++)
{
string constr = ConfigurationManager.ConnectionStrings["ConString2"].ConnectionString;
string sqlStatment = "INSERT INTO [Emails] ([From],[Subject],[Body],[Date]) VALUES (#From ,#Subject,#Body,#Date)";
using (SqlConnection con = new SqlConnection(constr))
{
using (SqlCommand cmd = new SqlCommand(sqlStatment, con))
{
con.Open();
cmd.Parameters.AddWithValue("#From", this.Emails[i].From);
cmd.Parameters.AddWithValue("#Subject", this.Emails[i].Subject);
cmd.Parameters.AddWithValue("#Body", this.Emails[i].Body);
cmd.Parameters.AddWithValue("#Date", this.Emails[i].DateSent);
cmd.ExecuteNonQuery();
con.Close();
}
}
}
}
For the architecture of this you can try creating something like this:
External systems: Will write to the sql database
Database: Only needs one table. With possibly these columns (to give you an idea)
Receiver
Sender
IsSent
BodyMessage
SentTime
Sender: A sender application/service that will query the database at regular intervals for unsent emails and send them.
If you wonder how you technically query and insert into a SQL database then that's something there are plenty of resources on.
Simply trying to find out the correct syntax for my connection string. Before anyone asks, yes I did look at other SO answers, and no they did not work for me. Here a couple of attempts I made from looking at other SO questions like the one I am asking
Server=(local);Database=SalesOrdersExample;Integrated Security= true
Data Source=(local);Database=SalesOrdersExample;Integrated Security=SSPI
Server=.\\SQLEXPRESS;Database=SalesOrdersExampleDataSet;Integrated Security=true
None of them worked (I have a Console.WriteLine("test"); thrown in there and it works up until I try conn.Open() (opening the connection to database) so I'm assuming that it must be my connection string since nothing gets written after conn.Open())
Console.WriteLine("test"); // works
SqlConnection conn = new SqlConnection("Server=.\\SQLEXPRESS;Database=SalesOrdersExampleDataSet;Integrated Security=true");
Console.WriteLine("test"); // works
conn.Open();
Console.WriteLine("test"); // does not work
So some information about the database is that it's local under my 'Data Connections' in my Server Explorer. I also have the .xsd file in my project so I have linked the Data Set to the current project I am on. Here is a picture representation to confirm that I have both the Data Connection and the Data Set.
EDIT: SO does not allow me to post pictures until I have 10 rep so here is direct link to picture:
DB Screenshot
Any help is appreciated thank you.
Visual Studio comes with LocalDB database, which is not exactly SQL Server Express database.
Try something like this:
Server=(localdb)\v11.0;Integrated Security=true;
or
Data Source=(LocalDB)\v11.0; AttachDbFileName=|DataDirectory|\DatabaseFileName.mdf; InitialCatalog=DatabaseName;Integrated Security=True;MultipleActiveResultSets=True
If using in c# code, you can use # to avoid problems with backslash characters:
SqlConnection conn =
new SqlConnection(#"Server=(localdb)\v11.0;Integrated Security=true;");
I'm using SQL Azure in a Windows Azure app running as a cloud service. Most of the time my database actions works completely fine (that is, after handling all sorts of timeouts and what not), however i'm running into a problem that seems
using (var connection = new SqlConnection(m_connectionString))
{
m_ConnectionRetryPolicy.ExecuteAction(() => connection.Open());
using (var command = connection.CreateCommand())
{
command.CommandText = "SELECT * FROM X WHERE Y = Z";
var reader = m_CommandRetryPolicy.ExecuteAction(() => command.ExecuteReader());
return LoadData(reader).FirstOrDefault();
}
}
The line that fails is the Command.ExecuteReader with an:
ExecuteReader requires an open and available Connection. The connection's current state is closed
Things that i have already considered
I'm not "reusing" an old connection or saving a connection is a member variable
There should be no concurrency issues - the repository class that these methods belong to is created each time it is needed
Have anyone else experienced this? I could of course just add this to the list of exception which would yield a retry, but I'm not very comfortable with that as
I had a bunch of these errors a few days ago (West Europe) on my production deployment, but they went away by themselves. At the same time I was seeing timeouts, throttling and other errors from SQL Azure. I assume that there was a temporary problem with the platform (or at least the server that I am running on).
You probably aren't doing anything wrong in your code, but are suffering from degraded performance on SQL Azure. Try and handle the errors, perform retries, exponential back-off, queues (to reduce concurrency), splitting your load across databases — that sort of thing.
write every thing within try and catch,finally block.
as follows:
try
{
con.open();
m_ConnectionRetryPolicy.ExecuteAction(() => connection.Open());
using (var command = connection.CreateCommand())
{
command.CommandText = "SELECT * FROM X WHERE Y = Z";
var reader = m_CommandRetryPolicy.ExecuteAction(() => command.ExecuteReader());
return LoadData(reader).FirstOrDefault();
}
con.close();
}
catch(exception ex)
{
}
finally
{
con.close();
}
Remember to close connection in finally block as well.
There is an Enterprise Library that MS has produced specifically for SQL Azure, here are some examples from their patterns and Practice.
It's similar to what you are doing, however it does more on the reliability (and these examples show how to get a reliable connection)
http://msdn.microsoft.com/en-us/library/hh680899(v=pandp.50).aspx
Are you sure it's the reader that's failing and not the opening of the connection? I'm encountering an exception when I wrap the connection.Open() in the m_ConnectionRetryPolicy.ExecuteAction().
However it works just fine for me if I skip the ExecuteAction wrapper and open the connection using connection.OpenWithRetry(m_ConnectionRetryPolicy).
And I'm also using command.ExecuteReaderWithRetry(m_ConnectionRetryPolicy) which is working for me.
I have no idea though why it's not working when wrapped in ExecuteAction though.
I believe this means that Azure has closed the connection behind the scenes, without telling the connection pooler. This is by design. So, the connection pooler gives you what it thinks is an available, open connection, but when you try to use it, it finds out it's not open after all.
This seems very clunky to me, but it's the way Azure is at the moment.
I am using the following code to copy files from one folder to another...
Public Shared Sub CopyFlashScriptFile(ByVal SourceDirectory As String, ByVal DestinationDirectory As String)
Try
Dim f() As String = Directory.GetFiles(SourceDirectory)
For i As Integer = 0 To UBound(f)
File.Copy(f(i), DestinationDirectory & "\" & System.IO.Path.GetFileName(f(i)),True)
Next
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
The files I am copying are database files, .mdf and .ldf. Which are being used by the application. Now the problem is when I try to copy the files it throws an error
file is being used by another process
Can anyone help me with this?
Is there anyway I can programmatically stop SQL Server and copy the files, then start the server again?
To expand on my comment - I would build a .sql file with the T-SQL command to backup the database to another location, and then I can use sqlcmd from the command line in order to run the backup .sql file.
So to build the .sql file I would go through the process of backing up the database via SQL Server Management Studio. Here is a tutorial on how to do this:
http://www.serverintellect.com/support/sqlserver/database-backup-ssmse.aspx
Then, before clicking OK to perform the backup, click on the "Script" button on the backup window and choose "Script Action To New Query Window". This will generate the SQL of your settings from the backup database window. Save that SQL into a file and you're done.
Next is to use sqlcmd.exe to execute the .sql file to backup the database whenver you want. There is a very good example of using sqlcmd.exe from C# code here:
http://geekswithblogs.net/thomasweller/archive/2009/09/08/automating-database-script-execution.aspx
I always prefer doing stuff like this without affecting the running SQL Server (unless it's one running on my dev machine, where I'll happily stop/start the service). You just never what might happen if you stop a production SQL Server service to copy some files. Could be very costly, so better to be safe.
Depending on which version of SQL you are using you could make use of the Microsoft.SqlServer.Management.Smo.Wmi.Service objects to Start and Stop the Service that runs the SQL instance.
After doing this you should be able to simply copy the files as needed.
For SQL Server 2008
{
//Declare and create an instance of the ManagedComputer
//object that represents the WMI Provider services.
ManagedComputer mc;
mc = new ManagedComputer();
//Iterate through each service registered with the WMI Provider.
foreach (Service svc in mc.Services)
{
Console.WriteLine(svc.Name);
}
//Reference the Microsoft SQL Server service.
Service Mysvc = mc.Services["MSSQLSERVER"];
//Stop the service if it is running and report on the status
// continuously until it has stopped.
if (Mysvc.ServiceState == ServiceState.Running) {
Mysvc.Stop();
Console.WriteLine(string.Format("{0} service state is {1}", Mysvc.Name, Mysvc.ServiceState));
while (!(string.Format("{0}", Mysvc.ServiceState) == "Stopped")) {
Console.WriteLine(string.Format("{0}", Mysvc.ServiceState));
Mysvc.Refresh();
}
Console.WriteLine(string.Format("{0} service state is {1}", Mysvc.Name, Mysvc.ServiceState));
//Start the service and report on the status continuously
//until it has started.
Mysvc.Start();
while (!(string.Format("{0}", Mysvc.ServiceState) == "Running")) {
Console.WriteLine(string.Format("{0}", Mysvc.ServiceState));
Mysvc.Refresh();
}
Console.WriteLine(string.Format("{0} service state is {1}", Mysvc.Name, Mysvc.ServiceState));
Console.ReadLine();
}
else {
Console.WriteLine("SQL Server service is not running.");
Console.ReadLine();
}
}
From msdn
I am using the .mdf file in my application...in case of a system crash or format the user is going to loose the data..so if the user copies the data(.mdf) to some other drive ..he/she can replace the new .mdf file with the old one which has all there data...correct me if i am wrong...thanks.
That's exactly what "normal" backups are for.
As you noticed yourself, you can backup a SQL Server database by simply copying the .mdf and .ldf files, but the downside is that you can only do this when the SQL Server service is not running.
And stopping the SQL Server service just to backup the database is not a good idea, because your users can't access the database while the service is stopped.
Taking a "normal" backup (usually a .bak file) can be done while the database is running, so there's no need to stop SQL Server every time you want to make a backup.
There are several ways how to do a backup:
a) Manually in SQL Server Management Studio:
see the first link in Jason Evans' answer
b) If you want to take a backup regularly (say, once a day) you need to use sqlcmd.
Jason Evans described this in his answer as well, but IMO there's an easier way - you need only two files with one line each. See How to create jobs in SQL Server Express edition.
(if you were using a full SQL Server edition and not only Express, you could set up a Maintenance Task in Management Studio instead, but that's not possible in SQL Server Express, so you have to do it manually like described above).
we've got a real confusing problem. We're trying to test an SQL Bulk Load using a little app we've written that passes in the datafile XML, the schema, and the SQL database connection string.
It's a very straight-forward app, here's the main part of the code:
SQLXMLBULKLOADLib.SQLXMLBulkLoad4Class objBL = new SQLXMLBULKLOADLib.SQLXMLBulkLoad4Class();
objBL.ConnectionString = "provider=sqloledb;Data Source=SERVER\\SERVER; Database=Main;User Id=Username;Password=password;";
objBL.BulkLoad = true;
objBL.CheckConstraints = true;
objBL.ErrorLogFile = "error.xml";
objBL.KeepIdentity = false;
objBL.Execute("schema.xml", "data.xml");
As you can see, it's very simple but we're getting the following error from the library we're passing this stuff to: Interop.SQLXMLBULKLOADLib.dll.
The message reads:
Failure: Attempted to read or write protected memory. This is often an indication that other memory has been corrupted
We have no idea what's causing it or what it even means.
Before this we first had an error because SQLXML4.0 wasn't installed, so that was easy to fix. Then there was an error because it couldn't connect to the database (wrong connection string) - fixed. Now there's this and we are just baffled.
Thanks for any help. We're really scratching our heads!
I am not familiar with this particular utility (Interop.SQLXMLBULKLOADLib.dll), but have you checked that your XML validates to its schema .xsd file? Perhaps the dll could have issues with loading the xml data file into memory structures if it is invalid?
I try to understand your problem ,but i have more doubt in that,
If u have time try access the below link ,i think it will definitely useful for you
link text
I know I did something that raised this error message once, but (as often happens) the problem ended up having nothing to do with the error message. Not much help, alas.
Some troubleshooting ideas: try to determine the actual SQL command being generated and submitted by the application to SQL Server (SQL Profiler should help here), and run it as "close" to the database as possible--from within SSMS, using SQLCMD, direct BCP call, whatever is appropriate. Detailing all tests you make and the results you get may help.