Inserting exe file to database

FileStream fls = new FileStream(@filepath, FileMode.OpenOrCreate, FileAccess.Read);
                    byte[] blob = new byte[fls.Length];
                    fls.Read(blob, 0, System.Convert.ToInt32(fls.Length));
                    fls.Close();
                   string query = "update employee set doc = :BlobParameter ";
                        OracleParameter blobParameter = new OracleParameter();
                        blobParameter.OracleType = OracleType.Blob;
                        blobParameter.ParameterName = "BlobParameter";
                        blobParameter.Value = blob;
                        OracleCommand cmd = new OracleCommand(query,conn);
                        cmd.Parameters.Add(blobParameter);
                        cmd.ExecuteNonQuery();
                        conn.Close();
                        conn.Dispose();
                    }

string sql = "Select doc from employee where docId = '121'";
OracleCommand cmd = new OracleCommand(sql, conn);
OracleDataReader dataReader = cmd.ExecuteReader();
dataReader.Read();
OracleLob blob = dataReader.GetOracleLob(0);
dataReader.Close();
// Create a byte array
byte[] byteData = new byte[0];
// fetch the value of Oracle parameter into the byte array
byteData = (byte[])blob.Value;
// get the length of the byte array
int ArraySize = byteData.GetUpperBound(0);

// Write the Blob data fetched from database to the filesystem at the destination 
FileStream fs1 = new FileStream(FilePath, FileMode.OpenOrCreate , FileAccess.Write);
fs1.Write(byteData, 0, ArraySize);
fs1.Close();