There are various methods used in Joomla to display query results according to the requirement. They are as follows:

Single Value Result :

• loadResult():
  loadResult() method is used when a database query returns a single value. It is basically used with count query.
  For example:

  $db = JFactory::getDbo();
  $query = $db->getQuery(true);
  $query->select('COUNT(*)');
  $query->from($db->quoteName('#__yourtablename'));
  $query->where($db->quoteName('columnname')." = ".$db->quote($value));
  $db->setQuery($query);
  $count = $db->loadResult();

Single Row Results :

• loadRow():
  loadRow() method returns a single record in indexed array form.
  For example:

  $db = JFactory::getDbo();
  $query = $db->getQuery(true);
  $query->select('*');
  $query->from($db->quoteName('#__yourtablename'));
  $query->where($db->quoteName('columnname')." = ".$db->quote($value));
  $db->setQuery($query);
  $count = $db->loadRow();

• loadAssoc():
  loadAssoc() method returns a single record in associated array form.
  For example:

  $db = JFactory::getDbo();
  $query = $db->getQuery(true);
  $query->select('*');
  $query->from($db->quoteName('#__yourtablename'));
  $query->where($db->quoteName('columnname')." = ".$db->quote($value));
  $db->setQuery($query);
  $count = $db->loadAssoc();

• loadObject()
  loadObject() method returns a single record in PHP object form.
  For example:

  $db = JFactory::getDbo();
  $query = $db->getQuery(true);
  $query->select('*');
  $query->from($db->quoteName('#__yourtablename'));
  $query->where($db->quoteName('columnname')." = ".$db->quote($value));
  $db->setQuery($query);
  $count = $db->loadObject();

Single Column Results:

• loadColumn():
  loadColumn() method returns a single column in indexed array form.
  For example:

  $db = JFactory::getDbo();
  $query = $db->getQuery(true);
  $query->select('*');
  $query->from($db->quoteName('#__yourtablename'));
  $query->where($db->quoteName('columnname')." = ".$db->quote($value));
  $db->setQuery($query);
  $count = $db->loadColumn();

Multi-Row Results:

• loadRowList():
  loadRowList() method is used when the database query returns all the records of the table. It returns indexed array of indexed arrays.
  For example:

  $db = JFactory::getDbo();
  $query = $db->getQuery(true);
  $query->select('*');
  $query->from($db->quoteName('#__yourtablename'));
  // Reset the query using our newly populated query object.
  $db->setQuery($query);
  $count = $db->loadRowList();

• loadAssocList():
  loadAssocList() method is used when the database query returns all the records of the table. It returns indexed array of associated arrays.
  For example:

  $db = JFactory::getDbo();
  $query = $db->getQuery(true);
  $query->select('*');
  $query->from($db->quoteName('#__yourtablename'));
  // Reset the query using our newly populated query object.
  $db->setQuery($query);
  $count = $db->loadRowList();

• loadObjectList():
  loadObjectList() method is used when the database query returns all the records of the table. It returns indexed array of PHP objects.
  For example:

  $db = JFactory::getDbo();
  $query = $db->getQuery(true);
  $query->select('*');
  $query->from($db->quoteName('#__yourtablename'));
  // Reset the query using our newly populated query object.
  $db->setQuery($query);
  $count = $db->loadRowList();