Gorm: "created_at" is reset after db.Save(&user) in updating

[aliabdallahawad]

I know that gorm.db initialize the data of "created_at", "updated_at", "deleted_at" automatically

but i have a problem with function "db.Save(&obj)" that update the field "updated_at" but reset the field "created_at" to "0001-01-01T00:00:00Z"

Here's my code:

model.go

type CommentId struct {
    Id uint64 `json:"id" sql:"AUTO_INCREMENT"`
}

type CommentData struct {
    Message string `json:"message"`
    ObjectModel string `json:"objectModel"`
    ObjectId uint `json:"objectId"`
    SpaceId uint `json:"spaceId"`
}

type Comment struct {
    CommentId
    CommentData `json:"data"`
    Trace   `json:"trace"`
}

router.go

func PutComment(db gorm.DB, router *gin.Engine) {
    // PUT /comment
    // Update comment data by id
    router.PUT("/comment/:id", func(c *gin.Context) {
        _id := c.Param("id")
        if id, err := strconv.ParseUint(_id, 10, 64); err == nil {
            var commentData model.CommentData
            if err := c.BindJSON(&commentData); err == nil {
                comment := &model.Comment{
                    CommentData: commentData,
                    CommentId: model.CommentId {Id: id},
                }
                if err := checkDataComment(comment.CommentData); err {
                    checkComment := &model.Comment{
                        CommentData: commentData,
                        CommentId: model.CommentId {Id: id},
                    }
                    if err := db.First(checkComment).Error; err == nil {
                        db.Save(&comment) // reset "created_at field"
                        c.JSON(http.StatusOK, comment)
                    } else {
                        c.AbortWithStatus(http.StatusNotFound)
                    }
                } else {
                    c.AbortWithStatus(http.StatusBadRequest)
                }
            }
        } else {
            log.Print(err)
            c.AbortWithError(http.StatusBadRequest, err)
        }
    })
}

[alecha]

Exactly the same issue. I think that the save method should never overwrite the created_at field, now I have to manually get the old row and manually set the created_at field.

[jinzhu]

Hi @ali-abdalla , @alecha

Could you follow this guide to submit an executable script to confirm this issue?

https://github.com/jinzhu/gorm/blob/master/CONTRIBUTING.md

As in my daily use, haven't seen this problem?

[alecha]

I've created a Gist, hope it's clear.

[jinzhu]

@alecha I see, to me, I think we should keep the ability to for users to update any columns, including CreatedAt.

For your example, I have few suggestions:

• Find the user first, decode json the to object then save it, like:

db.First(&user, id)
// decode json to user
db.Save(&user)

• Only save selected attributes

db.Select("FirstName", "LastName").Save(&user)

• Use updates

db.Model(&user).Updates(attrs)

[alecha]

Using

db.Model(User{ID: u.ID}).Updates(u)

seems to solve the issue, but in case I want to set an empty string for a field it won't work right?

[jinzhu]

Yes, as there are no different for: User{}, User{FirstName: ""}, so won't update empty string

There is an issue explained this, and have some solutions for it.

[imbaMF]

Another and better way is Omit field:
db.Omit("created_at", "deleted_at").Save(&user)

[mosleim]

i just want to confirm. if have simple struct model like this:

    MCell struct {
        gorm.Model
        Name string `json:"name"`
        IP   string `json:"ip"`
    }

and i want to save after updating some of value of an cell object:

        cell := MCell{}
    db.FirstOrCreate(&cell, MCell{Name: "ASC1-B"})
    cell.IP = "192.168.5.31"
    db.Save(&cell)

and then, why all field value (except IP) reset?
name is blank, and created_at is zero date-time. and i'm passing cell.Name = cell.Name and then, error will happen(vet error)