根据gorm中的set if条件更新记录

type User struct {
    ID   uint
    Name string
    Age  int
}

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

func main() {
    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 {
        panic("Failed to connect to database")
    }
    // ...
}

func main() {
    // ...
    db.Model(&User{}).Where("age > ?", 18).Update("age", gorm.Expr("age + ?", 1))
    // ...
}

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

type User struct {
    ID   uint
    Name string
    Age  int
}

func main() {
    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 {
        panic("Failed to connect to database")
    }

    db.AutoMigrate(&User{})

    // 创建用户
    user := User{Name: "Alice", Age: 20}
    db.Create(&user)

    // 更新年龄
    db.Model(&User{}).Where("age > ?", 18).Update("age", gorm.Expr("age + ?", 1))
}