You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: set_db.go
    path of file: ./repos/iam/internal/iamctl/cmd/set
    
    the code of the file until where you have to start completion: // Copyright 2020 Lingfei Kong <colin404@foxmail.com>. All rights reserved.
// Use of this source code is governed by a MIT style
// license that can be found in the LICENSE file.

package set

import (
	"fmt"

	"g
    
func (o *DBOptions) ensureSchema() error {
	dsn := fmt.Sprintf("%s:%s@tcp(%s)/?charset=utf8", o.username, o.password, o.host)

	db, err := gorm.Open("mysql", dsn)
	if err != nil {
		return err
	}
	defer db.Close()

	if o.drop {
		dropSQL := fmt.Sprintf("DROP DATABASE IF EXISTS %s", o.Database)
		if err := db.Exec(dropSQL).Error; err != nil {
			return err
		}
		fmt.Fprintf(o.Out, "drop database %s success\n", o.Database)
	}

	createSQL := fmt.Sprintf("CREATE DATABASE if not exists %s CHARSET utf8 COLLATE utf8_general_ci", o.Database)
	if err := db.Exec(createSQL).Error; err != nil {
		return err
	}

	fmt.Fprintf(o.Out, "create database %s success\n", o.Database)

	return nil
}