Asp.net – Is it possible to convert gltf to byte array and then convert byte array back into a file?

The basic approach to save or retrieve a file from the database is:

Read the raw file into a byte[] array.

Save that byte[] array into the database.

And to retrieve the file?

Then get/load/query the database row.

Cast the binary column into a byte[] array.

Save/write the byte array to a file.

So, code to save a file into database will look like this:

(I’m using SQL server, not PostgreSQL, but the code should be near identical using the PostgreSQL .net database provider).

So, to save a file to the database, then this:

        string sFile = Server.MapPath($@"~/UpLoadFiles/control.pdf");
        byte[] FileAsBytes = File.ReadAllBytes(sFile); 

        string sFileNameOnly = Path.GetFileName(sFile);

        string strSQL =
            @"INSERT INTO tblFiles (FileName, UpLoaded, MineType, FileB)
            VALUES (@FileName, @UpLoaded, @MineType, @FileB)";

        SqlCommand cmdSQL = new SqlCommand(strSQL);

        cmdSQL.Parameters.Add("@FileName", SqlDbType.NVarChar).Value = sFileNameOnly;
        cmdSQL.Parameters.Add("@UpLoaded", SqlDbType.DateTime).Value = DateTime.Now;
        cmdSQL.Parameters.Add("@MineType", SqlDbType.NVarChar).Value =
            MimeMapping.GetMimeMapping(sFile);
        cmdSQL.Parameters.Add("@FileB", SqlDbType.Binary).Value = FileAsBytes;

        General.MyRstE(cmdSQL);

And to do the reverse, and get a file from the database, then this:

        int PK = 3;  // for testing database PK row id

        SqlCommand cmdSQL = new SqlCommand("SELECT * FROM tblFiles WHERE ID = @ID");
        cmdSQL.Parameters.Add("@ID", SqlDbType.Int).Value = PK;

        DataTable dt = General.MyRstP(cmdSQL);

        string strFile = dt.Rows[0]["FileName"].ToString();

        byte[] FileAsBytes = dt.Rows[0]["FileB"] as byte[]; 

        File.WriteAllBytes(strFile, FileAsBytes);   

I don’t know what column types are available in PostgreSQL, but a binary or blob type of column should exist, and using such a column type should allow the above process of converting a file to a byte[] array, and then sending that to the database.

And as the above shows, you reverse the process when wanting to get a valid file from the database. So, get the row you need, convert the blob/binary column to a byte array, and then save that byte array to a file.

Since we using a byte array, then the file type being text, pdf, a .dll, or whatever does not matter.

And I used in above some handy helper routines, since I don’t want to type over and over creating the database connection object, and command object.

So, the helper routines used above from my global static class was:

    public static DataTable MyRst(string strSQL)
    {
        DataTable rstData = new DataTable();
        using (SqlConnection conn = new SqlConnection(Properties.Settings.Default.TEST4))
        {
            using (SqlCommand cmdSQL = new SqlCommand(strSQL, conn))
            {
                cmdSQL.Connection.Open();
                rstData.Load(cmdSQL.ExecuteReader());
            }
        }
        return rstData;
    }


    public static DataTable MyRstP(SqlCommand cmdSQL)
    {
        DataTable rstData = new DataTable();
        using (SqlConnection conn = new SqlConnection(Properties.Settings.Default.TEST4))
        {
            using (cmdSQL)
            {
                cmdSQL.Connection = conn;
                conn.Open();
                rstData.Load(cmdSQL.ExecuteReader());
            }
        }
        return rstData;
    }


    public static void MyRstE(SqlCommand cmdSQL)
    {
        using (SqlConnection conn = new SqlConnection(Properties.Settings.Default.TEST4))
        {
            using (cmdSQL)
            {
                cmdSQL.Connection = conn;
                conn.Open();
                cmdSQL.ExecuteNonQuery();
            }
        }
    }