DataBase Connection

hi everybody;
my questions about when database connection :
i am when connecting database latter receiveing exception error.Error is : An unhandled exception of type 'System.Data.SqlServerCe.SqlCeException' occurred in System.Data.SqlServerCe.dll
codes :
SqlCeConnection cnn=new SqlCeConnection("Datasource=\\My Documents\\Business\\LOREAL.sdf");
cnn.Open(); // Exception is here
help me..
can i doing ?

Mehmet,

Try the code below instead - it fixes your connection string and provides you with a way to get more information about specific exceptions you may encounter using SQL Mobile.

-Darren

try

{

SqlCeConnection cnn = new SqlCeConnection(@."Data Source = \My Documents\Business\LOREAL.sdf");

cnn.Open();

}

catch (SqlCeException sqlex)
{
DisplaySQLCEErrors(sqlex);

}

public void DisplaySQLCEErrors(SqlCeException ex)
{
SqlCeErrorCollection errorCollection = ex.Errors;

StringBuilder bld = new StringBuilder();
Exception inner = ex.InnerException;

foreach (SqlCeError err in errorCollection)
{
bld.Append("\n Error Code: " + err.HResult.ToString("X"));
bld.Append("\n Message : " + err.Message);
bld.Append("\n Minor Err.: " + err.NativeError);
bld.Append("\n Source : " + err.Source);

foreach (int numPar in err.NumericErrorParameters)
{
if ( 0 != numPar ) bld.Append( "\n Num. Par. : " + numPar );
}

foreach ( string errPar in err.ErrorParameters )
{
if ( String.Empty != errPar ) bld.Append( "\n Err. Par. : " + errPar );
}

MessageBox.Show( bld.ToString(), "SQL Server CE Error" );
bld.Remove(0, bld.Length);
}
}

|||thank you Darren for my tring
and i am writing error Message :
ErrorCode:80004005
Message : There is a file sharing violation. A different process might be using the file.[,,,,,]
Mino Error .: 25035
Source: Microsoft SQL Server 2000 Windows CE Edition
Err.Par.:\My Documents\Business\LOREAL.sdf

help me (:|||

Something else on your device has a lock on the .SDF file. Try soft-resetting the device and run your code again. If that doesn't work, you may not have a clean install of SQL Mobile on the device.

Regards,

Darren

|||thank you Darren very very much
i am tring now and when being error message i will write is here (:|||but not do Darren..
i am reset machine and later i was set to program and i was install my application. but not did.
again same error...
can i doing ?
please help....|||

Mehmet,

Can you open the .sdf file using Query Analyzer 3.0 on your device? If that works and your application cannot create a connection to the database, there is some problem in your code and I'd ask you to post more of your code. If you cannot open the database with Query Analyzer 3.0, I'd be interested to know what error is reported. The error you are getting indicates that the .sdf fileis locked, but SQL Mobile is a multi-user database and can accept multiple connections. The only thing that I know of that would lock the entire database would be that you are running a Compact, AutoFlush, or merge repl with AddOption.CreateDatabase while you have code that is trying to connect to it. And it doesn't sound like that is the case.

Are you sure you have a good install of SQL Mobile and that the .sdf file is valid? How did you create your .sdf file?

Darren

|||hi again...
i am using SQL CE 2.0 in dotnet 2003 .
and my database running in PDA. and it s running on QueryAnalyzer.
but i am not connection database on codebehind in .net. and i sent code to you.
or i did writing code for create database on codebehind. Then creating database on PDA but again i am not connected database ):
and when i not connection open database later i am not running ExecuteReader or ExecuteNonQuery on PDA.
but no problem PDA.|||

SQL CE 2.0 allows only one connection to database, QA connection counts. Make sure to exit QA or you won't be able to open this database.

|||but my code is correct and my code is running on Windows Application.but not running on PDA application.
i reseted pda , i installed QA and i installed my program.
but again not running.
usually error is : An unhandled exception of type 'System.Data.SqlServerCe.SqlCeException' occurred in System.Data.SqlServerCe.dll
connection.Open(); /// exception is here
or not running code is : SqlDataAdapter.Fill(DataTable); // not running code..|||

I’m not quite sure how your code can run on Windows application because SQL Server CE 2.0 is not available on desktop. Even if it does, it does not mean it would run unchanged on device.

This exception you're getting means something wrong with your code, data and/or environment. Error messages in the exception would tell you what it is, so you can fix your application code, data or environment.

If that's the same message as before, please make sure you're not running another copy of your application, you do not open more than one connection to the same DB from your application and you do not have Query Analyzer running at the same time as your application.

|||

pls help me as soon as possible.I am getting an error as

An unhandled exception of type 'System.Data.SqlServerCe.SqlCeException' occurred in System.Data.SqlServerCe.dll

|||first only not running your database (sdf) on query analyzer..
usually your code first : connection.open()
command.ExecuteNonQuery();
connection.Close();
for example.....
if you opened connection and end your process later close connection...|||Hi, Darren;
I am facing this same problem.
I am quite sure that no other process is trying to connect my .sdf file.
My code is:
....
conn.Close();
conn.Open();//open connection just after close; throw exception.

The reason that close connection and open again is that if I still use this open connection (passed in as parameter), I got exception sth like "...connection is Fetching...". So I close and then open it. It works most of the time, but it throws that exception. I looks like connection hasn't been closed but try to open it again. I add code:
...
conn.Close();
int count = 0;
while (conn.State != ConnectionState.Closed)
{
Thread.Sleep(250);
if(count>4)
break;
count++;
}
conn.Open();
...
it still throws that exception.
How can I fix that problem?

Thank u very much.

|||

Hi everbody,

I have a problem like this.There is a programme on PDA and it has a (.sdf) database .When I trying to start program,I got this error : "not access to user table" and then "it will be upgrade" and then "25035: There is a file sharing violation.A different process might be using the file"

and when I look at the database,I saw three tables: MSysConstraints,MSysObjects,MSysRDATombstone.

I supposed that the database havent a "user table" ,but I dont know what serve the three tables on the database.

thanks much..