Language: C # / ASP.NET
Database: PostgreeSQL
Component used to upload the file: FileUpload
The following is the component:
Hereisthemethodtoinsertatableinthedatabasethatonlyhasthefields:
attachment_id/attachment_name/attachment
Andfinallythemethodtoopenthefile:
And the result of this method is:
In this example I uploaded a .jpg image and it gave me this result error. I am not able to recover any files.
What's wrong with my methods, I still can not visualize ... Thank you.
The problem occurs because you are not writing the contents of the file correctly.
By its code, the Attachment property of the AnexoBLL class is of type byte [] . At the point in the code you create the SQL string that will be executed in the database, you are simply concatenating the byte property [] with a string. This will not cause the property value to be used, but the framework will internally use the .ToString () method of type byte [], which will return the type name. Soon your query would look something like:
insert into tb_anexo (nome_arquivo, anexo) values ('imagem.jpg', 'System.Byte[]')
Correct would be the use of parameters, not only for the code to work, but because it is a good practice and avoids even SQL injection problems. To enter, use the code as follows (adapt to use your connection):
Npgsql.NpgsqlCommand command = new Npgsql.NpgsqlCommand();
command.CommandText = "insert into tb_anexo (nome_arquivo, anexo) values (:nome_arquivo, :anexo)";
command.Parameters.AddWithValue("nome_arquivo", anexo.NomeArquivo);
command.Parameters.AddWithValue("anexo",NpgsqlDbType.Bytea, anexo.Arquivo);
command.ExecuteNonQuery();
I'm assuming you're using the correct type in your column, which in this case should be bytea (see more at