Driver.ColumnCount only works when debugging

OK, first of all, if TestID is -1, you don't need to declare the SQL query.. the assumption is that, if you don't alter the command text, it's always going to be a select all.  So, I'd simply do an if then to check if TestID != -1... if that returns true, set the query, otherwise, do nothing but continue with your test.

So... my guess is that, in debugging, TestID is -1... so, you never set your SQL query to the queryByID SQL statement.  Hence, you'll not get the error... because my guess is that you're running an SQL query for a column called TestID that is an integer and not a string... so, that's the type mismatch.  Try the following code:

function testve()
{
  var csvPath = "C:\\TestData\\FrameFields.csv";
  QueryCSVByID(csvPath,"FrameFields.csv",1);
}

function QueryCSVByID(csvPath,csvName,testID)
{  
  let colCount = 0;
  let Driver = DDT.CSVDriver(csvPath); 
    
  if (testID != -1)
  {
    var queryByID = 'SELECT * FROM ' + csvName  + ' WHERE  TestID = ' + testID + ';
    Driver.ADOCommandObject.CommandText = queryByID;
    //aqUtils.Delay(10000)
  }
  //aqUtils.Delay(10000);
  colCount = Driver.ColumnCount;<-Fails at runtime, unless I'm debugging.

  while(!Driver. EOF())
  {
      for(var i = 0; i < colCount - 1 ;i++)
      {
        Log.Message("Column " + i + " name is " + Driver.ColumnName(i) + " and it's value is " + Driver.Value(i));
      }  
    Driver.Next();   
    Log.Message("---------------------------- ROW --------------------------------------------") ;
  }  
}