JDatabase Update +1

Question

I am trying to update the database with the original column's value plus (+1) or minus (-1)

$column_name = 'mycolumnname';
$table_name - 'mytablename';

$db = JFactory::getDbo();
$query = $db->getQuery(true);
$fields = array($db->quoteName($column_name) . ' = ' . $db->quote($column_name +1));
$query->update($db->quoteName($table_name))->set($fields);
$db->setQuery($query);
$result = $db->execute();

If i run this it will always set the column value to 1. What am i doing wrong?

Answer 1

Try

$db->quoteName($column_name) . ' = ' . $db->quoteName($column_name).'+ 1'

instead of

$db->quoteName($column_name) . ' = ' . $db->quote($column_name +1)

If you echo $query you will see the MySQL command it is going to execute.

UPDATE `mycolumnname` SET `mycolumnname` = `mycolumnname`+ 1 

Adding a number to a string casts it as a number, hence it returns 1 when you generate the query using $db->quote($column_name +1));.