Gorm updates zero-value problem solution ideas and processes

CREATE TABLE `foods` (
  `id` int(11) NOT NULL AUTO_INCREMENT COMMENT 'Product ID',
  `title` varchar(100) NOT NULL COMMENT 'Trade Name',
  `price` float DEFAULT '0' COMMENT 'Commodity Price',
  `stock` int(11) DEFAULT '0' COMMENT 'Commodity Inventory',
  `type` int(11) DEFAULT '0' COMMENT 'Product Type',
  `create_time` datetime NOT NULL COMMENT 'Product creation time',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

//commoditytype Food struct {
	Id         int
	Title      string
	Price      float32
	Stock      int
	Type       int
	//mysql datetime, date type field, can be bound to golang type. For detailed instructions, please refer to the chapter on the Gorm connection database.	CreateTime 
}
//Bind table name for Foodfunc (v Food) TableName() string {
	return "foods"
}

food := Food{}
//First query a record and save it in the model variable food//Equivalent to: SELECT * FROM `foods` WHERE (id = '2') LIMIT 1("id = ?", 2).Take(&food)
//Modify the value of the food model = 100
//Equivalent to: UPDATE `foods` SET `title` = 'Cola', `type` = '0', `price` = '100', `stock` = '26', `create_time` = '2018-11-06 11:12:04' WHERE `foods`.`id` = '2'(&food)

//Example 1://Update the table record corresponding to the food model//Equivalent to: UPDATE `foods` SET `price` = '25' WHERE `foods`.`id` = '2'(&food).Update("price", 25)
//Update the price field value by using the value of the primary key id of the food model as the where condition.//Example 2://The above example is just to update a record. What if we want to make all records more?//Equivalent to: UPDATE `foods` SET `price` = '25'(Food{}).Update("price", 25)
//Note that the Model parameter here uses Food{}, a new blank model variable is generated without any records bound.//Because the id of Food{} is empty, the gorm library will not use id as a condition, and the where statement is empty//Example 3://Update records based on custom conditions, not based on primary key id//Equivalent to: UPDATE `foods` SET `price` = '25' WHERE (create_time > '2018-11-06 20:00:00')(Food{}).Where("create_time > ?", "2018-11-06 20:00:00").Update("price", 25)

//Example 1://Update fields through structure variable settingsupdataFood := Food{
		Price:120,
		Title:"Lemon Sprite",
	}
//Update database records according to food model//Equivalent to: UPDATE `foods` SET `price` = '120', `title` = 'lemon Sprite' WHERE `foods`.`id` = '2'//Updates will ignore the zero value field of the updateFood structure variable, so the generated SQL statements only have price and title fields.(&food).Updates(&updataFood)
//Example 2://Update records based on custom conditions, not based on model idupdataFood := Food{
		Stock:120,
		Title:"Lemon Sprite",
	}
//Set Where conditions, Model parameters bind an empty model variable//Equivalent to: UPDATE `foods` SET `stock` = '120', `title` = 'lemon Sprite' WHERE (price > '10')(Food{}).Where("price > ?", 10).Updates(&updataFood)
//Example 3://What should I do if I want to update all field values, including zero values, but I don’t want to ignore empty fields?//Use map type to replace the above structure variable//Define map type, key is string, value is interface{} type, convenient to save any valuedata := make(map[string]interface{})
data["stock"] = 0 //Zero Value Fielddata["price"] = 35
//Equivalent to: UPDATE `foods` SET `price` = '35', `stock` = '0' WHERE (id = '2')(Food{}).Where("id = ?", 2).Updates(data)

UPDATE foods SET stock = stock + 1 WHERE id = '2'

//Equivalent to: UPDATE `foods` SET `stock` = stock + 1 WHERE `foods`.`id` = '2'(&food).Update("stock", ("stock + 1"))

user:=User{
	Name:"",
	Age:0,
	Actived:false,
}
(&user).Updates(user)
//These zero values ​​will not be updated at this time. If you need to update the zero values, use mapuserMap:=map[string]interface{}{
  "name":"",
  "age":0,
  "actived":0,
}
(&user).Updates(userMap)