cakephp / phinx

        $indexes = $this->getIndexes($tableName);

        $columns = array_map('strtoupper', $columns);

        foreach ($indexes as $indexName => $index) {

            $a = array_diff($columns, $index['columns']);

            if (empty($a)) {

                $this->execute(

                    sprintf(

                        'DROP INDEX %s',

                        $this->quoteColumnName($indexName)

                    )

                );

                break;

            }

        }

    }

    /**

        $columns = array_map('strtolower', $columns);

        $instructions = new AlterInstructions();

        foreach ($indexes as $index) {

            $a = array_diff($columns, $index['columns']);

            if (empty($a)) {

                $instructions->addPostStep(sprintf(

                    'DROP INDEX %s',

                    $this->quoteColumnName($index['index'])

                ));

            }

        }

        return $instructions;

    }