DboSource::addColumn PHP Method

    public function addColumn($options)
    {
        extract($options);
        if (!isset($table) || !isset($column)) {
            return false;
        }
        if (!isset($column['name'])) {
            if (isset($field)) {
                $column['name'] = $field;
            } else {
                return false;
            }
        }
        $old = $this->readSchema($table);
        if (isset($old['tables'][$table][$field])) {
            return false;
        }
        $new = $old;
        // 配列の順番を考慮して新しいフィールドを追加しないと、$CakeSchema->compare() で、
        // 間違った構成の情報を取得してしまう。（tableParametersをフィールドとして解析してしまう）
        $fields = array();
        foreach ($new['tables'][$table] as $key => $value) {
            if ($key !== 'indexes' && $key !== 'tableParameters') {
                $fields[$key] = $value;
            }
        }
        $fields[$field] = $column;
        if (!empty($new['tables'][$table]['indexes'])) {
            $fields['indexes'] = $new['tables'][$table]['indexes'];
        }
        if (isset($new['tables'][$table]['tableParameters'])) {
            $fields['tableParameters'] = $new['tables'][$table]['tableParameters'];
        }
        $new['tables'][$table] = $fields;
        $CakeSchema = ClassRegistry::init('CakeSchema');
        $CakeSchema->connection = $this->configKeyName;
        $compare = $CakeSchema->compare($old, $new);
        $sql = $this->alterSchema($compare);
        return $this->execute($sql);
    }