Develop Reference

IBM.Data.DB2.Core error in new DB2Connection(connectionString)

We have the IBM.Data.DB2.Core (3.1.0.300) nuget package installed in our .netstandard2.1 application library, to connect to an external DB2 instance on prem.
On running the following code from a .net core azure function v3 Windows 64bit (from a netcoreapp3.1 project)
var connectionString= "Server=DB2_IP:DB2_Port;Database=DB2_DBNAME;UID=DB2_UserId;PWD=DB2_Password;"
var connection = new DB2Connection(connectionString);
(note the values in the connection string are placeholders for anonymity)
We are receiving the following error
IBM.Data.DB2.Core.DB2Exception (0x80004005): ERROR [58005] [IBM][DB2.NET] SQL0902 An unexpected
exception has occurred in
Process: 21308 Thread 33 AppDomain: Name:Microsoft.Azure.WebJobs.Script.WebHost
There are no context policies. Function: AESEncryptADONET (Encryption Info)
CallStack: at System.Environment.get_StackTrace()
at IBM.Data.DB2.Core.DB2ConnPool.HandleUnknownErrors(String strFncMsg, Exception exception, Boolean bThrow)
at IBM.Data.DB2.Core.DB2ConnPool.EncryptString(String value)
at IBM.Data.DB2.Core.DB2ConnPool.ReplaceConnectionStringParms(DB2Connection connection, String szValue, DB2ConnSettings& pSettings, DB2ConnSettingsInternal& pSettingsInternal, Boolean bAttach, Boolean pushDownStrAppended)
at IBM.Data.DB2.Core.DB2Connection.set_ConnectionString(String value)
at IBM.Data.DB2.Core.DB2Connection..ctor(String connectionString)
Does anyone have any idea where we're going wrong, or alternatively have a coherent end-to-end guide on the setup that may give me a clue.
All documentations I have found thus far has been rather sparse and a little inconsistent.

SQLite BackupDatabase method is throwing exception after upgrading to version 1.0.111.0

I am upgrading System.Data.SQLite from version 1.0.93.0 to 1.0.111.0
I am having a method which copies the SQLite database on disk to in memory. It is working fine with version 1.0.93.0 and here's the code in VB.Net
Dim sourceConn = CType(_connection, System.Data.SQLite.SQLiteConnection)
Dim destConn = CType(destDBM._connection, System.Data.SQLite.SQLiteConnection)
sourceConn.BackupDatabase(destConn, "main", "main", -1, Nothing, 0)
where path of destination SQLite is in memory by using ":memory:" instead of path.
After upgrading to version 1.0.111.0, it throws the below exception
code = Unknown (-1), message = System.Data.SQLite.SQLiteException (0x80004005): unknown error
failed to initialize backup
at System.Data.SQLite.SQLite3.InitializeBackup(SQLiteConnection destCnn, String destName, String sourceName)
at System.Data.SQLite.SQLiteConnection.BackupDatabase(SQLiteConnection destination, String destinationName, String sourceName, Int32 pages, SQLiteBackupCallback callback, Int32 retryMilliseconds)
Does anyone have any idea that how to get it solved?

I am able to find out the root cause of this issue myself. Actually, I was starting a transaction in destination database before backup. It was working fine in the older version but the behavior is changed in the latest version and exception is not meaningful at all.
To fix it, I have re-ordered the code which was initiating transaction as the next step after taking backup. It's working as expected now and insertions are way too fast in the latest version. Great work by SQLite team!

getting Mono with firebird-embedded working on 64bit Linux environment

I'm trying to get Firebird-embedded 2.5 (64bit) on Linux with firebird .net provider (FirebirdSql.Data.FirebirdClient) working.
The FB embedded setup for my Test assembly is working on WinX86_64 with the Windows Firebird Embedded version.
On Linux I use the coresponding FB embedded Linux version placed files in the assembly directory:
libfbembed.so*
firebird.msg
security2.fdb
libicu*
libib*
Set the "RootDirectory" to assembly directory in the firebird.conf.
Set the shell environment variables LD_LIBRARY_PATH and FIREBIRD to to assembly directory.
FbConnectionStringBuilder conn = new FbConnectionStringBuilder();
conn.Database = #"/home/dev/firebirdTest/1stDB.FDB";
conn.ServerType = FbServerType.Embedded;
conn.UserID = "SYSDBA";
conn.Password = "masterkey";
conn.Charset = "UTF8";
conn.DataSource = "localhost";
conn.ClientLibrary = "libfbembed.so";
string connStr = conn.ConnectionString;
var dbcon = new FbConnection(connStr);
FbConnection.CreateDatabase(connStr, pageSize: 8192, forcedWrites: true, overwrite: false);
dbcon = new FbConnection(connStr);
dbcon.Open();
what I did before:
Redirecting the Firebird Clientlibrary by mono dllmap doesn't work. Solved by explicit setting the ClientLib in C# code.
manually creating a Database with isql on Linux works.
creating a Database by code on Linux works.
the Firebird .NET provider creates in debug mode the FB_{sanitizedName}.dll and DynamicAssembly.dll
the .NET provider is really silent. Debugging was done by starting the assembly with "strace mono {testAssembly.exe}" on linux.
FbConnection.CreateDatabase crashes with I/O error during "open O_CREAT" (calling FbCreateDatabase), if pagesize is not 8192. Setting explicit pagesize to 8192 solves this.
Now, I run in following errors ( and stuck here for days...):
Opening an existing Databasefile (like in the code here), crashes with:
FirebirdSql.Data.FirebirdClient.FbException: invalid database handle (no active connection) ---> invalid database handle (no active connection)
What's going wrong?

I've stuck with this error too.
FirebirdSql.Data.FirebirdClient.FbException: invalid database handle (no active connection)
Tried with FB 2.5.* and 3.0.0 results are the same.
Also tried using debug builds of FB. Logs did not help.
Maybe somebody here knows what the problem is?

It's 3 years since the original post, and I've run into the same problem. I don't have an "answer" but I do have an explanation. It appears the marshalling of SafeHandle objects isn't fully implemented in mono. From their documentation on SafeHandle: "Notice that “ref SafeHandles” pass a pointer to a slot containing zero to P/Invoked methods, and on return the a new SafeHandle is created with the returned value. “ref SafeHandles” do not actually get the original SafeHandle.handle value."
If you look into the FirebirdClient source, in IFbClient, you'll see the P/Invoke declarations look like:
IntPtr isc_detach_database(
[In, Out] IntPtr[] statusVector,
[MarshalAs(UnmanagedType.I4)] ref DatabaseHandle dbHandle);
DatabaseHandle is derived from SafeHandle, so the second argument is a "ref SafeHandle" argument, and suffers from the problem noted above - it will basically pass in a zero rather than the actual handle value.
There is no fix other than to (a) improve the SafeHandle implementation in mono, or (b) rewrite FirebirdClient to avoid the use of SafeHandles.

Accessing member of Microsoft.SqlServer.Management.Smo.Server object crashes exactly once

We are trying to access the DefaultFile member of an Microsoft.SqlServer.Management.Smo.Server object. After a lot of debugging, it turns out that accessing the member crashes the first time, but can then be accessed just fine. Looking at the variable in a debug window returns an exception the first time, the correct value the second and all following times.
The first access of either server.DefaultFile or server.DefaultLog throws an exception like this:
System.IndexOutOfRangeException: Index was outside the bounds of the array.
at Microsoft.SqlServer.Management.Smo.BitStorage.SetBit(Int32 itemIndex, BitIndex bitIndex, Boolean value)
at Microsoft.SqlServer.Management.Smo.PropertyCollection.SetRetrieved(Int32 index, Boolean val)
at Microsoft.SqlServer.Management.Smo.SqlSmoObject.AddObjectPropsFromDataReader(IDataReader reader, Boolean skipIfDirty, Int32 startColIdx, Int32 endColIdx)
at Microsoft.SqlServer.Management.Smo.SqlSmoObject.ImplInitialize(String[] fields, OrderBy[] orderby)
at Microsoft.SqlServer.Management.Smo.SqlSmoObject.Initialize(Boolean allProperties)
at Microsoft.SqlServer.Management.Smo.SqlSmoObject.OnPropertyMissing(String propname, Boolean useDefaultValue)
at Microsoft.SqlServer.Management.Smo.PropertyCollection.GetValueWithNullReplacement(String propertyName, Boolean throwOnNullValue, Boolean useDefaultOnMissingValue)
at Microsoft.SqlServer.Management.Smo.Server.get_DefaultFile()
at my function... etc etc
The first-access-crash is very concistent, so doing something terrible like below gets around the problem completely:
using (var sqlConnection = new SqlConnection(sourceDatabaseConnectionString.ConnectionString))
{
var svrConnection = new ServerConnection(sqlConnection);
var server = new Server(svrConnection);
// begin mega hack
try
{
// crashes on first access
var dummy = server.DefaultFile;
}
catch
{
// do absolutely nothing
}
// end mega hack
// business as usual...
var defaultFile = server.DefaultFile;
}
Of course, we don't like code like this (even if it's only in our internal tools) so any ideas of why this might be happening is welcome. Our only clue is that we've recently upgraded some instances of SQL Server 2012 to SQL Server 2014. We can sometimes get around the issue when running the code locally on a machine with SQL Server 2014 installed. The production machine that runs this code does not have an installation at all, but references DLLs. However, we can't find any differences in the versions used when debug printing the assembly versions while running the code.

I've seen similar messages when using an older version of SMO, especially when trying to use 2008R2 SMO to access 2012. Upgrading to the installs from 2008R2 Featurepack SP3 fixed my issues.
Check that there's not a more recent version of the Shared Management Objects + CLR Types + Native client driver that you could use.

no combination of intermediate filters could be found

I'm making a windows form application using Visual Studio. The application allows you to enter the what you want the photo to be named, and then saves that image to a specific location on the network. It works great when I use it on my laptop. However, when I try to run it on the a desktop, it does not work. Instead I get the message:
System.Runtime.InteropServices.COMException (0x80040217): No
combination of intermediate filters could be found to make the
connection.
at DirectShowLib.DsError.ThrowExceptionForHR(Int32 hr)
at OrderProductCapture.Capture.SetupGraph(DsDevice dev, Int32 iWidth,
Int32 iHeight, Int16 iBPP, Control hControl)
at OrderProductCapture.Capture.ctor(Int32 iDeviceNum, Int32 iWidth,
Int32 iHeight, Int16 iBPP, Control hControl)
at OrderProductCapture.frmMain.ctor()
The Call Stack says:
OrderProductCapture.exe!OrderProductCapture.Capture(int iDeviceNum, int iWidth, int iHeight, short iBPP, System.Windows.Forms.Control hControl) Line 82
OrderProductCapture.exe!OrderProductCapture.frmMain.frmMain() Line 50
OrderProductCapture.exe!OrderProductCapture.Program.Main() Line 19
I have already googled this many times, and I've looked at most of the similar questions on SO. Both computers are using Windows 7 professional. Any help would be fantastic.
This is the code where my code catches the exception. I do not think the code is wrong, because it works fine on my laptop.
public Capture(int iDeviceNum, int iWidth, int iHeight, short iBPP, Control hControl)
{
DsDevice [] capDevices;
// Get the collection of video devices
capDevices = DsDevice.GetDevicesOfCat(FilterCategory.VideoInputDevice);
if (iDeviceNum + 1 > capDevices.Length)
{
throw new Exception("No video capture devices found at that index!");
}
try
{
// Set up the capture graph
SetupGraph( capDevices[iDeviceNum], iWidth, iHeight, iBPP, hControl);
// tell the callback to ignore new images
m_PictureReady = new ManualResetEvent(false);
}
catch
{
Dispose();
throw;
}
}

When having to convert between media formats, you can programmatically force it to use some specific filter chain and configure it tightly to your needs, but DirectSHOW also has the ability of "guessing" the right tools to use. It knows all the tiny media handlers that are oficially installed in the OS, and tries to match them so that final required "conversion" is built.
However, DirectShow still needs those tiny converters to be installed. DS is able to analyze and connect them, but will not provide you any support for exotic media types. Often, even non-exotic can be problematic if the OS is "fresh-n-clean".
If I remember correctly, that error basically means that (on this problematic machine) some "codecs" are missing.
These things often come with any:
drivers for webcams/microphones/soundcards
audio-processing software (sound editors, media recorders, media players, ..)
"codec packs" like CCCP (really, don't get confused by their logo)
specific codec/filter packages
(...)
First thing I'd now do would be:
recall what I tried to convert
try to read all error messages and logs and find out if there's some faulty filter mentioned, maybe it needs reinstalling
compare what audio-related software is installed on machines where the program WORKS versus the problematic machine
basing on the above, try to deduce what codec is missing
find it, download, install
Also, you may read the code of SetupGraph() function. I bet there's a clear reference to the format that is being used, and this may point out what codec is missing.
Codecs also sometimes get damaged (actually not themselves, but their configuration and registration entries may get damaged). If you are sure that the correct codecs are available on the machine, reinstalling or "repairing" (if they have such option) them can help.