library/Rediska/Command/Decrement.php
public function create($key, $amount = 1)
    {
        $connection = $this->_rediska->getConnectionByKeyName($key);

        if ($amount == 1) {
            $command = array('DECR',
                             $this->_rediska->getOption('namespace') . $key);
        } else {
            $command = array('DECRBY',
                             $this->_rediska->getOption('namespace') . $key,
                             $amount);
        }

        return new Rediska_Connection_Exec($connection, $command);
    }
public function create($key, $amount = 1)
    {
        $connection = $this->_rediska->getConnectionByKeyName($key);

        if ($amount == 1) {
            $command = array('DECR',
                             $this->_rediska->getOption('namespace') . $key);
        } else {
            $command = array('DECRBY',
                             $this->_rediska->getOption('namespace') . $key,
                             $amount);
        }

        return new Rediska_Connection_Exec($connection, $command);
    }
Create command

@param string            $key    Key name
@param integer[optional] $amount Amount to decrement. One for default
@return Rediska_Connection_Exec