See the details here
//ensure the file will only be called from within Joomla
defined('_JEXEC') or die();
// get a reference to the form model - as we are importing line by line, the form model contains the current
// data that we are going to submit to the table.
$formModel = $listModel->getFormModel();
// the record's data is stored in the array 'formData' - to alter the element 'us_streets___street_desc' to the value 'testing' we use the following line:
$formModel->formData['us_streets___street_desc'] = "testing";
//ensure the file will only be called from within Joomla
defined('_JEXEC') or die();
// get a reference to the form model - as we are importing line by line, the form model contains the current
// data that we are going to submit to the table.
$listModel = $this->getModel();
$formModel = $listModel->getFormModel();
// the record's data is stored in the array 'formData' - to alter the element 'us_streets___street_desc' to the value 'testing' we use the following line:
$formModel->formData['us_streets___street_desc'] = "testing";
//ensure the file will only be called from within Joomla
defined('_JEXEC') or die();
// get a reference to the form model - as we are importing line by line, the form model contains the current
// data that we are going to submit to the table.
$formModel = $tableModel->getForm();
// the record's data is stored in the array 'formData' - to alter the element 'us_streets___street_desc' to the value 'testing' we use the following line:
$formModel->formData['us_streets___street_desc'] = "testing";