Multi Column selection from a Sqlite table

[nagabathula]

hello .. I have a problem with multiple column selection, This is what i am doing to access a single column.. How could i select only the column names i.e( Channels ) which i have selected i have appended the list of selected column names in a QVector.. How can i use the column names from this vector in the query to access only those channel data.
" QSqlQuery sq1("select Thermo2 from thdata where rowid = (" + QString::number(rowcnt) + ")");" Instead of a single column Thermo2 i need to pass how many ever channels were selected.. I have created a column for each channel in the db,say i have 300 columns for 300 channels.. In case i select only 100 columns in random i sud be able to retrieve only those columns of data.. I have all the selected channel names in a QVector called columnnames but don't know how to pass multiple columns to the Query . I am calling this function with a QTimer every 500 milli sec.

QSqlQuery sq1("select Thermo2 from thdata where rowid = (" + QString::number(rowcnt) + ")");
	if(sq1.exec())
	{
		if (sq1.first())
		{
			do
			{
				for (int i = 0; i < tepdata.size(); ++i)
				{
					tepdata.push_back(sq1.value(i).toString());
					rowcnt++;
 
				}
			} while(sq1.next());
		}
//qDebug()<< tepdata

QSqlQuery sq1("select Thermo2 from thdata where rowid = (" + QString::number(rowcnt) + ")");
	if(sq1.exec())
	{
		if (sq1.first())
		{
			do
			{
				for (int i = 0; i < tepdata.size(); ++i)
				{
					tepdata.push_back(sq1.value(i).toString());
					rowcnt++;
					
				}
			} while(sq1.next());
		}
//qDebug()<< tepdata

To copy to clipboard, switch view to plain text mode 

;
Pls help me ,i will be really great full this is very important for me.. i have been trying to get a solution past 2 days but have no answer, i searched a lot din't find any much help.

thanks a lot.