github.com/alesjr/optimisticlock

Optimisticlock

Optimisticlock is optimistic lock plugin for gorm.

Usage

import "gorm.io/plugin/optimisticlock"

type User struct {
  ID      int
  Name    string
  Age     uint
  Version optimisticlock.Version
}

var user User
DB.First(&user)

DB.Model(&user).Update("age", 18)
// UPDATE `users` SET `age`=18,`version`=`version`+1 WHERE `users`.`version` = 1 AND `id` = 1

// Ignores the Version value passed to the structure
DB.Model(&user).Updates(&User{Age: 18, Version: optimisticlock.Version{Int64: 1}})
// UPDATE `users` SET `age`=18,`version`=`version`+1 WHERE `users`.`version` = 2 AND `id` = 1

DB.Model(&User{}).Where("id = 1").Update("age", 12)
// UPDATE `users` SET `age`=12,`version`=`version`+1 WHERE id = 1


DB.Transaction(func(tx *gorm.DB) error {
	
	tx.First(&user)
    
	user.Age = 18
	rows = tx.Updates(&user).RowsAffected 
	// rows=1
	
	user.Age = 19
	rows = tx.Updates(&user).RowsAffected 
	// rows=0, Because user.Version not updated
	
	return nil
})