backend/cmd/migrate/main.go

package main

import (
	"flag"
	"fmt"
	"log"

	"gorm.io/driver/postgres"
	"gorm.io/gorm"
)

// Config 数据库配置
type Config struct {
	Host     string
	Port     int
	User     string
	Password string
	DBName   string
	SSLMode  string
}

type PostImage struct {
	ID              string `gorm:"type:varchar(36);primaryKey"`
	PostID          string `gorm:"type:varchar(36);index"`
	URL             string `gorm:"type:text"`
	ThumbnailURL    string `gorm:"type:text"`
	PreviewURL      string `gorm:"type:text"`
	PreviewURLLarge string `gorm:"type:text"`
	Width           int    `gorm:"default:0"`
	Height          int    `gorm:"default:0"`
	Size            int64  `gorm:"default:0"`
	MimeType        string `gorm:"type:varchar(50)"`
	SortOrder       int    `gorm:"default:0"`
}

func (PostImage) TableName() string {
	return "post_images"
}

func main() {
	// 解析命令行参数
	host := flag.String("host", "localhost", "数据库主机")
	port := flag.Int("port", 5432, "数据库端口")
	user := flag.String("user", "postgres", "数据库用户")
	password := flag.String("password", "", "数据库密码")
	dbname := flag.String("dbname", "carrot_bbs", "数据库名称")
	sslmode := flag.String("sslmode", "disable", "SSL 模式")
	flag.Parse()

	cfg := &Config{
		Host:     *host,
		Port:     *port,
		User:     *user,
		Password: *password,
		DBName:   *dbname,
		SSLMode:  *sslmode,
	}

	// 连接数据库
	dsn := fmt.Sprintf("host=%s port=%d user=%s password=%s dbname=%s sslmode=%s",
		cfg.Host, cfg.Port, cfg.User, cfg.Password, cfg.DBName, cfg.SSLMode)

	db, err := gorm.Open(postgres.Open(dsn), &gorm.Config{})
	if err != nil {
		log.Fatalf("Failed to connect to database: %v", err)
	}

	// 测试连接
	sqlDB, err := db.DB()
	if err != nil {
		log.Fatalf("Failed to get database instance: %v", err)
	}
	defer sqlDB.Close()

	if err := sqlDB.Ping(); err != nil {
		log.Fatalf("Failed to ping database: %v", err)
	}

	log.Println("Connected to database")

	// 运行迁移
	if err := runMigration(db); err != nil {
		log.Fatalf("Migration failed: %v", err)
	}

	log.Println("Migration completed successfully")
}

func runMigration(db *gorm.DB) error {
	// 检查字段是否已存在
	columns, err := db.Migrator().ColumnTypes(&PostImage{})
	if err != nil {
		return fmt.Errorf("failed to check column existence: %w", err)
	}

	hasPreviewURL := false
	hasPreviewURLLarge := false
	for _, col := range columns {
		if col.Name() == "preview_url" {
			hasPreviewURL = true
		}
		if col.Name() == "preview_url_large" {
			hasPreviewURLLarge = true
		}
	}

	if hasPreviewURL && hasPreviewURLLarge {
		log.Println("Columns already exist, skipping migration")
		return nil
	}

	// 添加字段
	if !hasPreviewURL {
		log.Println("Adding preview_url column...")
		if err := db.Exec("ALTER TABLE post_images ADD COLUMN preview_url TEXT").Error; err != nil {
			return fmt.Errorf("failed to add preview_url column: %w", err)
		}
	}

	if !hasPreviewURLLarge {
		log.Println("Adding preview_url_large column...")
		if err := db.Exec("ALTER TABLE post_images ADD COLUMN preview_url_large TEXT").Error; err != nil {
			return fmt.Errorf("failed to add preview_url_large column: %w", err)
		}
	}

	log.Println("Migration completed successfully")
	return nil
}

// 注意：此脚本仅用于添加数据库字段
// 预览图的生成由后端的 upload_service 自动处理
// 现有图片需要重新上传才能生成预览图，或者编写额外的后台任务来生成