使用 GORM 与 MySQL 数据库进行交互来实现增删改查（CRUD）操作

1、安装 GORM 和 MySQL 驱动

新版本库是gorm.io/gorm

go get -u gorm.io/gorm

go get -u gorm.io/driver/mysql

2、连接 MySQL 数据库

package main

import (
    "gorm.io/driver/mysql"
    "gorm.io/gorm"
    "log"
)

func main() {
    // 数据源名称 (DSN) 格式：username:password@tcp(127.0.0.1:3306)/dbname?charset=utf8mb4&parseTime=True&loc=Local
    dsn := "user:password@tcp(127.0.0.1:3306)/dbname?charset=utf8mb4&parseTime=True&loc=Local"
    db, err := gorm.Open(mysql.Open(dsn), &gorm.Config{})
    if err != nil {
        log.Fatalf("failed to connect database: %v", err)
    }
    log.Println("Connected to the MySQL database successfully.")
}

请根据实际情况替换 dsn 中的 user, password, 127.0.0.1:3306, dbname

3、定义模型

定义一个简单的模型，例如 Product，用于映射到数据库表。

type Product struct {
    gorm.Model
    Code  string
    Price uint
}

这里的 gorm.Model 包含了 ID、CreatedAt、UpdatedAt 和 DeletedAt 字段。

4、完整示例

package main

import (
	"log"

	"gorm.io/driver/mysql"
	"gorm.io/gorm"
)

type Product struct {
	gorm.Model
	Code  string
	Price uint
}

func main() {
	dsn := "root:123456@tcp(127.0.0.1:3306)/test?charset=utf8mb4&parseTime=True&loc=Local"
	db, err := gorm.Open(mysql.Open(dsn), &gorm.Config{})
	if err != nil {
		log.Fatalf("failed to connect database: %v", err)
	}
	log.Println("Connected to the MySQL database successfully.")

	// 自动创建或迁移表
	db.AutoMigrate(&Product{})

	// 创建
	product := Product{Code: "D42", Price: 100}
	result := db.Create(&product)
	if result.Error != nil {
		log.Fatalf("Failed to create record: %v", result.Error)
	} else {
		log.Printf("Created product with ID: %d", product.ID)
	}

	// 查询
	var retrievedProduct Product
	if err := db.First(&retrievedProduct, 1).Error; err != nil {
		log.Printf("Product not found: %v", err)
	} else {
		log.Printf("Found product: %+v", retrievedProduct)
	}

	// 更新
	product.Price = 150
	result = db.Save(&product)
	if result.Error != nil {
		log.Fatalf("Failed to update record: %v", result.Error)
	} else {
		log.Printf("Updated product: %+v", product)
	}

	// 删除
	result = db.Delete(&product)
	if result.Error != nil {
		log.Fatalf("Failed to delete record: %v", result.Error)
	} else {
		log.Printf("Deleted product with ID: %d", product.ID)
	}
}