go-gorm

Posted at 2020-07-31 golang gorm

官方文档已经很详细的对gorm的使用方法进行介绍了。

连接数据库

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args := "root:root1234@(localhost:3306)/gamedb?charset=utf8mb4&parseTime=True&loc=Local"
db,err = gorm.Open("mysql",args)
db.LogMode(true) // 开启日志，会打印sql语句

操作数据库

查询表是否存在

db.HasTable(&user)
db.HasTable(&User{})
db.HasTable("users")

创建表

db.CreateTable(&user)

删除表

db.DropTable(&User{})
db.DropTable("user")
db.DropTableIfExist(&User{},"prodcuts") //删除两张表

修改表

修改列
db.Model(&User).ModifyColumn("description","text") //修改description列为text
删除列
db.Model(&User{}).DropColumn("description")

操作表数据

创建数据

db.Create(&user)

查询数据

db.First(&user) // SELECT * FROM users ORDER BY id LIMIT 1;
db.Last(&user) //  SELECT * FROM users ORDER BY id DESC LIMIT 1;
db.Find(&users) //  SELECT * FROM users;
db.First(&user,10) // SELECT * FROM users WHERE id = 10
db.Where("name = ?","jinzhu").First(&user) //  SELECT * FROM users WHERE name = 'jinzhu' limit 1;

Where函数里面使用?作为拼接。

Where("name <> ?", "jinzhu")
Where("name in (?)", []string{"jinzhu", "jinzhu 2"})
Where("name LIKE ?", "%jin%")
Where("name = ? AND age >= ?", "jinzhu", "22")
Where("updated_at > ?", lastWeek)
Where("created_at BETWEEN ? AND ?", lastWeek, today)

Struct和map作为查询条件

// Struct
db.Where(&User{Name: "jinzhu", Age: 20}).First(&user)
//// SELECT * FROM users WHERE name = "jinzhu" AND age = 20 LIMIT 1;

// Map
db.Where(map[string]interface{}{"name": "jinzhu", "age": 20}).Find(&users)
//// SELECT * FROM users WHERE name = "jinzhu" AND age = 20;

// 主键的Slice
db.Where([]int64{20, 21, 22}).Find(&users)
//// SELECT * FROM users WHERE id IN (20, 21, 22);

修改数据

删除数据

坑位

unsupported Scan, storing driver.Value type []uint8 into type *time.Time

解决办法:数据库连接使用parseTime=true便可以解决

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