内容简介:flame/gorm/model/user.goflame/gorm/model/creditCard.goflame/gorm/model/phone.go
表设计
CREATE TABLE `user` ( `id` int(11) unsigned NOT NULL AUTO_INCREMENT COMMENT '自增ID', `name` varchar(64) NOT NULL DEFAULT '' COMMENT '用户名', `age` int(11) NOT NULL DEFAULT '0' COMMENT '年龄', `birthday` datetime NOT NULL DEFAULT '1000-01-01 00:00:00' COMMENT '生日', `email` varchar(128) NOT NULL DEFAULT '' COMMENT 'email', `credit_card_id` int(11) NOT NULL DEFAULT '0' COMMENT '信用卡ID', `created_at` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间', `deleted_at` datetime NOT NULL DEFAULT '1000-01-01 00:00:00' COMMENT '删除时间', `updated_at` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '更新时间', PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci COMMENT='用户表'; CREATE TABLE `credit_card` ( `id` int(11) unsigned NOT NULL AUTO_INCREMENT COMMENT '自增ID', `number` varchar(64) NOT NULL DEFAULT '' COMMENT '卡号', `user_id` int(11) NOT NULL DEFAULT '0' COMMENT '用户ID', `created_at` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间', `deleted_at` datetime NOT NULL DEFAULT '1000-01-01 00:00:00' COMMENT '删除时间', `updated_at` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '更新时间', PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci COMMENT='信用卡表'; CREATE TABLE `phone` ( `id` int(11) unsigned NOT NULL AUTO_INCREMENT COMMENT '自增ID', `number` varchar(64) NOT NULL DEFAULT '' COMMENT '手机号', `user_id` int(11) NOT NULL DEFAULT '0' COMMENT '用户ID', `created_at` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间', `deleted_at` datetime NOT NULL DEFAULT '1000-01-01 00:00:00' COMMENT '删除时间', `updated_at` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '更新时间', PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci COMMENT='手机号表'; CREATE TABLE `language` ( `id` int(11) unsigned NOT NULL AUTO_INCREMENT COMMENT '自增ID', `name` varchar(64) NOT NULL DEFAULT '' COMMENT '语言名称', `created_at` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间', `deleted_at` datetime NOT NULL DEFAULT '1000-01-01 00:00:00' COMMENT '删除时间', `updated_at` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '更新时间', PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci COMMENT='语言表'; CREATE TABLE `user_language` ( `id` int(11) unsigned NOT NULL AUTO_INCREMENT COMMENT '自增ID', `user_id` int(11) NOT NULL DEFAULT '0' COMMENT '用户ID', `language_id` int(11) NOT NULL DEFAULT '0' COMMENT '语言ID', `created_at` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间', `deleted_at` datetime NOT NULL DEFAULT '1000-01-01 00:00:00' COMMENT '删除时间', `updated_at` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '更新时间', PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci COMMENT='用户语言关联表';
模型
flame/gorm/model/user.go
package model import ( "github.com/jinzhu/gorm" "time" ) type User struct { gorm.Model Name string Age uint Birthday *time.Time //数据库字段值可以为NULL 时得使用指针,否则可以不用指针 Email string CreditCard *CreditCard //避免循环嵌套,使用指针形式 //has one 模型 //不填foreignkey,默认就是【此字段type】【CreditCard】+primarykey【ID】 为【CreditCardID】 //不填association_foreignkey,默认就是【此字段type】【User】的 primarykey【ID】, //即`gorm:"foreignkey:CreditCardID;association_foreignkey:ID"` CreditCardID uint //为foreignkey,在本struct内 ,指向拥有哪个信用卡 //foreignkey【CreditCard】.【CreditCardID】———————>association_foreignkey【CreditCard】.【ID】 Phones []Phone `gorm:"foreignkey:UserID"` //has many 模型 必须要配置foreignkey //不填association_foreignkey,默认就是【此struct】【User】的 primarykey【ID】, //即`gorm:"foreignkey:UserID;association_foreignkey:ID"` //association_foreignkey【User】.【ID】———————>foreignkey【Phone】.【UserID】 Languages []Language `gorm:"many2many:user_language;"` //many to many 模型 必须要配置many2many //关联表为user_language //不填foreignkey,默认就是【此struct】【User】的 primarykey【ID】 //不填association_foreignkey,默认就是【此字段type】【Language】的 primarykey【ID】 //不填jointable_foreignkey,默认就是【此struct】【User】+primarykey【ID】 为【UserID】 转换成【user_id】 //不填association_jointable_foreignkey,默认就是【此字段type】【Language】+primarykey【ID】 为【LanguageID】 转换成【language_id】 //foreignkey【User】.【ID】———————>jointable_foreignkey【user_language】.【user_id】 //association_jointable_foreignkey【user_language】.【language_id】———————>不填association_foreignkey【Language】.【I】 //多对多 存在循环时使用指针,否则可以不用指针,避免循环嵌套 }
flame/gorm/model/creditCard.go
package model import ( "github.com/jinzhu/gorm" ) type CreditCard struct { gorm.Model Number string User *User //避免循环嵌套,使用指针形式 //belong to模型 //不填foreignkey,默认就是【此字段type】【User】+primarykey【ID】 为【UserID】 //不填association_foreignkey,默认就是此字段type【User】的 primarykey【ID】, //即`gorm:"foreignkey:UserID;association_foreignkey:ID"` UserID int //为foreignkey, 在本struct内 ,指向归属哪个User //foreignkey【CreditCard】.【UserID】———————>association_foreignkey【User】.【ID】 }
flame/gorm/model/phone.go
package model import ( "github.com/jinzhu/gorm" ) type Phone struct { gorm.Model Number string User User //belong to模型 //不填foreignkey,默认就是此字段type【User】+primarykey【ID】 为【UserID】 //不填association_foreignkey,默认就是此字段type【User】的 primarykey【ID】, //即`gorm:"foreignkey:UserID;association_foreignkey:ID"` UserID int //为foreignkey, 在本struct内 ,指向归属哪个User //foreignkey【CreditCard】.【UserID】———————>association_foreignkey【User】.【ID】 }
flame/gorm/model/language.go
package model import ( "github.com/jinzhu/gorm" ) type Language struct { gorm.Model Name string }
repository
flame/gorm/repository/User.go
package repository import ( "errors" "github.com/jinzhu/gorm" "flame/gorm/model" ) type UserRepository interface { GetUserById(id int) (user model.User, err error) } func NewUserRepository(db *gorm.DB) UserRepository { return &userDBRepository{db: db} } type userDBRepository struct { db *gorm.DB } func(this *userDBRepository) GetUserById(id int)(user model.User, err error){ err = this.db.Where("id = ?", id).First(&user).Error if err != nil { return model.User{}, errors.New("查询失败") } return user, nil }
dbinstance
flame/gorm/dbinstance/mysql.go
package dbinstance import ( "fmt" "os" "log" "sync" "github.com/jinzhu/gorm" _ "github.com/jinzhu/gorm/dialects/mysql" ) var mysqlManager *MysqlManager var mysqlOnce sync.Once func GetMysqlInstance() *MysqlManager{ mysqlOnce.Do(func(){ mysqlManager=new(MysqlManager) mysqlManager.init() }) return mysqlManager } type MysqlManager struct { DB *gorm.DB ErrorMsg error } func (this *MysqlManager) init() (*gorm.DB,error) { this.DB, this.ErrorMsg = gorm.Open("mysql", "<user>:<password>@tcp(<host>:<port>)/<db>?charset=utf8mb4&parseTime=True&loc=Local") fmt.Println(this.ErrorMsg) if this.ErrorMsg != nil { log.Fatal(this.ErrorMsg) } else { this.DB.SingularTable(true)//表名为单数版 this.DB.LogMode(true) //输出日志 this.DB.SetLogger(log.New(os.Stdout, "\r\n", 0))//输出到控制台 } return this.DB,this.ErrorMsg } func (this *MysqlManager) Destroy(){ this.DB.Close() }
main 测试
flame/gorm/main.go
package main import ( "fmt" "flame/gorm/dbinstance" "flame/gorm/repository" ) func main(){ mysqlManager:=dbinstance.GetMysqlInstance() defer mysqlManager.Destroy() db:=mysqlManager.DB userDBRepository:=repository.NewUserRepository(db) user,err:=userDBRepository.GetUserById(1) fmt.Println(user) fmt.Println(err) }
运行得到输出
<nil> sql/home/flame/go/src/flame/gorm/repository/User.go:243.526054msSELECT * FROM `user` WHERE `user`.`deleted_at` IS NULL AND ((id = ?)) ORDER BY `user`.`id` ASC LIMIT 1[1] 0 {{0 0001-01-01 00:00:00 +0000 UTC 0001-01-01 00:00:00 +0000 UTC <nil>} 0 <nil> <nil> 0 [] []} 查询失败
由于gorm 判断带有deleted_at 字段就会根据这个值是否NULL来判断是否删除,
而我数据库字段设计是
deleted_at` datetime NOT NULL DEFAULT '1000-01-01 00:00:00' COMMENT '删除时间',
有默认值,所以获取不到结果
以上所述就是小编给大家介绍的《gorm 初步研究实例》,希望对大家有所帮助,如果大家有任何疑问请给我留言,小编会及时回复大家的。在此也非常感谢大家对 码农网 的支持!
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