CommonQuery::where PHP Method

    public function where($condition, $parameters = array())
    {
        if ($condition === null) {
            return $this->resetClause('WHERE');
        }
        if (!$condition) {
            return $this;
        }
        if (is_array($condition)) {
            // where(array("column1" => 1, "column2 > ?" => 2))
            foreach ($condition as $key => $val) {
                $this->where($key, $val);
            }
            return $this;
        }
        $args = func_get_args();
        if (count($args) == 1) {
            return $this->addStatement('WHERE', $condition);
        }
        // check that there are 2 arguments, a condition and a parameter value
        // if the condition contains a parameter simply add them
        // since its up to the user if it's valid sql or not
        // Otherwise we're probably with just an identifier. So lets
        // construct a new condition based on the passed parameter value.
        if (count($args) == 2 && !preg_match('/(\\?|:\\w+)/i', $condition)) {
            // condition is column only
            if (is_null($parameters)) {
                return $this->addStatement('WHERE', "{$condition} is NULL");
            } elseif (is_array($args[1])) {
                $in = $this->quote($args[1]);
                return $this->addStatement('WHERE', "{$condition} IN {$in}");
            }
            $condition = "{$condition} = ?";
        }
        array_shift($args);
        return $this->addStatement('WHERE', $condition, $args);
    }