Inserting special characters in database with IBM.

I've been having an issue with an app written in VB.Net that relies on an iSeries database. Users can save notes, which (very) often are copy/pasted from their mailbox.

But many mails contain invalid characters that trigger iDb2ConversionException when the data is saved to the database.

For the time being, I scrub the data, replacing invalid characters with matching html entities, but I really dislike that approach :

I have to maintain a conversion list, and even though I managed to cover most invalid characters, new ones always come up.
If I run the same command using STRSQL in Client Access, I can actually insert those invalid characters.
We have many fixed-length fields, and replacing chars with HTML entities makes it a lot harder to enforce maximum string lengths at the UI level

The same command works with ADO.NET if I don't use parameters (but then I have to scrub user input again, so all in all... it just moves the problem elsewhere)

Dim command = connection.CreateCommand()
command.CommandText = "UPDATE table SET field = '€€€€€]]]]]]]]]]]°°°°°°§§§§§' where ...."
command.ExecuteNonQuery() ' Executes successfully '

Dim command = connection.CreateCommand()
command.CommandText = "UPDATE table SET field = @value where ...."
command.DeriveParameters()
command.Parameters("@value").Value = "'€€€€€]]]]]]]]]]]°°°°°°§§§§§'"
command.ExecuteNonQuery() ' Throws iDb2ConversionException '

My connection string is as follows :

Datasource=server;DataBase=DBNAME;DefaultCollection=DBCOLLECTION;HexParserOption=Binary;LibraryList=LIBRARIES;Naming=SQL;DataCompression=True;AllowUnsupportedChar=true;

Is there any option available to successfully write those characters to the DB without getting that exception ?

Well, finally got it. All it takes is to change the CCSSID of the physical file (it had been compiled a while with CCSID 297).

CHGPF FILE(MYLIB/MYFILE) CCSID(xxxx)

In my case, I'm using CCSID 65535. However, with this one, storing strings is not as straightforward, I have to extract the byte array of my string :

Dim command = connection.CreateCommand()
command.CommandText = "UPDATE table SET field = @value where ...."
command.DeriveParameters()
command.Parameters("@value").Value = Encoding.Unicode.GetBytes("'€€€€€]]]]]]]]]]]°°°°°°§§§§§'")
command.ExecuteNonQuery() ' Works... '

But the good thing is that I can store virtually any character now :)