cakephp / phinx

    {

        $instructions = new AlterInstructions();

        foreach ($columns as $column) {

            $rows = $this->fetchAll(sprintf(

                "SELECT

                    CONSTRAINT_NAME

                  FROM information_schema.KEY_COLUMN_USAGE

                  WHERE REFERENCED_TABLE_SCHEMA = DATABASE()

                    AND REFERENCED_TABLE_NAME IS NOT NULL

                    AND TABLE_NAME = '%s'

                    AND COLUMN_NAME = '%s'

                  ORDER BY POSITION_IN_UNIQUE_CONSTRAINT",

                $tableName,

                $column

            ));

            foreach ($rows as $row) {

                $instructions->merge($this->getDropForeignKeyInstructions($tableName, $row['CONSTRAINT_NAME']));

            }

        }

        if (empty($instructions->getAlterParts())) {

            throw new \InvalidArgumentException(sprintf(

    {

        $instructions = new AlterInstructions();

        foreach ($columns as $column) {

            $rows = $this->fetchAll(sprintf(

                "SELECT

                tc.constraint_name,

                tc.table_name, kcu.column_name,

                ccu.table_name AS referenced_table_name,

                ccu.column_name AS referenced_column_name

            FROM

                information_schema.table_constraints AS tc

                JOIN information_schema.key_column_usage AS kcu ON tc.constraint_name = kcu.constraint_name

                JOIN information_schema.constraint_column_usage AS ccu ON ccu.constraint_name = tc.constraint_name

            WHERE constraint_type = 'FOREIGN KEY' AND tc.table_name = '%s' and ccu.column_name='%s'

            ORDER BY kcu.ordinal_position",

                $tableName,

                $column

            ));

            foreach ($rows as $row) {

                $instructions->merge(

                    $this->getDropForeignKeyInstructions($tableName, $row['constraint_name'])

                );

            }

        }

        return $instructions;

    }