Greetings, I'm trying to create a program that automatically update a blob field of a table, i know that the data in the blob field is text but don't know much more about it.
is there any way to read/update this field? this is my code so far:

Qt Code: 
  1. void conecta2::retrieveblob()
  2. {
  3.     conectdbisam();
  4.     QByteArray blob;
  5.     QString line;
  6.     QString line2;
  7.     QString tabla = "sfixed";
  8.     QString pointer = "55542";
  9.     int h,k,o;
  10.     h=0;
  11.     k=1;  //this is the code column that should match with "pointer"
  12.     o=4;  //this is the blob column
  13.     if(db.open())
  14.     {
  15.         QSqlQuery qry;
  16.         if(qry.exec("SELECT * FROM "+tabla))
  17.         {
  18.             QSqlRecord rec = qry.record();
  19.             columna = rec.fieldName(k);
  20.         }
  21.         if(qry.exec("SELECT * FROM "+tabla+" WHERE "+columna+" = '"+pointer+"'"))
  22.         {
  23.             while(qry.next())
  24.             {
  25.                 blob= qry.value(o).toByteArray();
  26.                 line2 = line.fromAscii(blob);
  27.                 qDebug() << "line blob "+line2;
  28.                 h++;
  29.                 if (h==500)
  30.                 break;
  31.             }
  32.         }
  33.     }
  34.     else
  35.     {
  36.         qDebug() << "Error =" << db.lastError().text();
  37.     }
  38. }
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this return "line blob " meaning that the string line2 is empty, what am I doing wrong?
Thanks in advance