gorm操练记录

这个数据库的定义蛮全的，先作个记录。

package main

import (
	"time"

	"github.com/jinzhu/gorm"
	_ "github.com/jinzhu/gorm/dialects/mysql"
)

type User struct {
	gorm.Model
	Birthday time.Time
	Age      int
	Name     string `gorm:"size:255"`       // string默认长度为255, 使用这种tag重设。
	Num      int    `gorm:"AUTO_INCREMENT"` // 自增

	CreditCard CreditCard // One-To-One (拥有一个 - CreditCard表的UserID作外键)
	Emails     []Email    // One-To-Many (拥有多个 - Email表的UserID作外键)

	BillingAddress Address // One-To-One (属于 - 本表的BillingAddressID作外键)
	//BillingAddressID sql.NullInt64

	ShippingAddress   Address // One-To-One (属于 - 本表的ShippingAddressID作外键)
	ShippingAddressID int

	IgnoreMe  int        `gorm:"-"`                         // 忽略这个字段
	Languages []Language `gorm:"many2many:user_languages;"` // Many-To-Many , 'user_languages'是连接表
}

type Email struct {
	ID         int
	UserID     int    `gorm:"index"`                          // 外键 (属于), tag `index`是为该列创建索引
	Email      string `gorm:"type:varchar(100);unique_index"` // `type`设置sql类型, `unique_index` 为该列设置唯一索引
	Subscribed bool
}

type Address struct {
	ID       int
	Address1 string `gorm:"not null;unique"` // 设置字段为非空并唯一
	Address2 string `gorm:"type:varchar(100);unique"`
	//Post     sql.NullString `gorm:"not null"`
}

type Language struct {
	ID   int
	Name string `gorm:"index:idx_name_code"` // 创建索引并命名，如果找到其他相同名称的索引则创建组合索引
	Code string `gorm:"index:idx_name_code"` // `unique_index` also works
}

type CreditCard struct {
	gorm.Model
	UserID uint
	Number string
}

func main() {
	db, err := gorm.Open("mysql", "root:password@(127.0.0.1:3306)/gorm?charset=utf8&parseTime=True&loc=Local")
	if err != nil {
		panic(err)
	}
	db.DB().SetMaxIdleConns(10)
	db.DB().SetMaxOpenConns(100)
	db.SingularTable(true)
	defer db.Close()

	// 自动迁移模式
	db.AutoMigrate(&User{}, &Email{}, &Address{}, &Language{}, &CreditCard{})
	/*
		db.Create(&Product{Code: "L1212", Price: 1000})

		// 读取
		var product Product
		db.First(&product, 1)                   // 查询id为1的product
		db.First(&product, "code = ?", "L1212") // 查询code为l1212的product

		// 更新 - 更新product的price为2000
		db.Model(&product).Update("Price", 2000)

		// 删除 - 删除product
		db.Delete(&product)

			tx := db.Begin()
			r1 := db.DropTable(&Address{})
			r2 := db.DropTableIfExists(&CreditCard{})
			if r1.Error != nil || r2.Error != nil {
				tx.Rollback()
				return
			}
			tx.Commit()
	*/
}