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UTF-8 Encoding (C# & PostgreSQL/Npgsql)

Posted on 2006-06-09
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Last Modified: 2007-12-19
Hello,

I'm writing a C# desktop application (.NET 1.1). The application simply retrieves a list of files in a directory and inserts it into a table. I'm getting the Npgsql.NpgsqlException: "ERROR: 22021: invalid UTF-8 byte sequence detected near byte 0x80". The strange thing is that this only happens with some files.

The program is very simple:

public static void main ()
{
   string [] files = System.IO.Directory.GetFiles("C:\\Temp");
   for (int i=0; i<files.Length; i++)
   {
      ExecuteNonQuery(files[i]);
   }
}

public static int ExecuteNonQuery (string filename)
{
   string sql = "";
   int  rowsAffected   = 0;
   Npgsql.NpgsqlCommand   npgsqlCommand   = null;
   Npgsql.NpgsqlConnection   npgsqlConnection      = null;

   // The query formed is: INSERT INTO "Image" VALUES (DEFAULT, 'C:\Temp\10x10.jpg', 0, 0, 0)
   sql = "INSERT INTO \"Image\" VALUES (DEFAULT, '" + filename + "', 0, 0, 0)";

   npgsqlConnection   = new Npgsql.NpgsqlConnection();
   npgsqlConnection.ConnectionString   = "The relevant connection string";
   npgsqlConnection.Open();

   npgsqlCommand   = new Npgsql.NpgsqlCommand(sql, npgsqlConnection);
   rowsAffected   = npgsqlCommand.ExecuteNonQuery();

   npgsqlConnection.Close();

   return (rowsAffected);
}

The target database is UTF-8 encoded. If I use a constant string for the filename parameneter, the code works fine.

How can I forcefully convert the sql statement to UTF-8?

Thanks,

Khan
0
Comment
Question by:raheelasadkhan
  • 2
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4 Comments
 
LVL 44

Expert Comment

by:bruintje
ID: 16875660
Hi raheelasadkhan,
----------

you could look at the UTF8Encoding class
http://msdn2.microsoft.com/en-us/s064f8w2.aspx

----------
bruintje
share what you know, learn what you don't
0
 

Author Comment

by:raheelasadkhan
ID: 16875856
Hi,

I've already read up on the Encoding class and it's built-in implementations.

Take this as an example:
   string [] files = System.IO.Directory.GetFiles("C:\\Temp");
   string sql = "INSERT INTO \"TableName\" VALUES ('" + files[0] + "')"

This sql statement causes the error I explained in my previous message.

I can't find a working example to convert [sql] into a valid UTF-8 format. In fact, I'm not even sure what format [sql] is in the forst place.

Thanks,

Khan
0
 
LVL 44

Accepted Solution

by:
bruintje earned 500 total points
ID: 16875934
i read something about putting "encoding=unicode" into the connection string, this way the connection to the db is setup with the encoding

does that help?
0
 

Author Comment

by:raheelasadkhan
ID: 16876136
I'll look that up and try it. Thanks
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