Doctrine\DBAL\Platforms\SQLServerPlatform::getDropIndexSQL PHP Method

    public function getDropIndexSQL($index, $table = null)
    {
        if ($index instanceof Index) {
            $index = $index->getQuotedName($this);
        } elseif (!is_string($index)) {
            throw new \InvalidArgumentException('AbstractPlatform::getDropIndexSQL() expects $index parameter to be string or \\Doctrine\\DBAL\\Schema\\Index.');
        }
        if (!isset($table)) {
            return 'DROP INDEX ' . $index;
        }
        if ($table instanceof Table) {
            $table = $table->getQuotedName($this);
        }
        return "IF EXISTS (SELECT * FROM sysobjects WHERE name = '{$index}')\n                    ALTER TABLE " . $table . " DROP CONSTRAINT " . $index . "\n                ELSE\n                    DROP INDEX " . $index . " ON " . $table;
    }