Gorm serialize struct on save/create

Question

I have struct, that is model for table. All was good, until I want to add type struct into it and serialize it to json (Location).

type Dome struct {
    gorm.Model
    Location Location `json:"location" gorm:"serializer:json"`
    Title    string   `json:"title" gorm:"type:varchar(100)"`
}

type Location struct {
    X1 int
    Y1 int
    X2 int
    Y2 int
}

When doing .Updates(), those values are serialized and saved into column. But when doing Create or Save, it throw error

sql: converting argument $ type: unsupported type Location, a struct

From what I understood, Gorm already have some default serializers, like json. And it seems to work on Updates, but not on any Create. Also when debugging I see those values deserialized and again in struct.

I can't find answer what am I missing, maybe need to add something else, but I am not that experienced. How to do that serialization into column from struct using Gorm?

user_2145830 · Answer

package main

import (
    "fmt"
    "gorm.io/driver/sqlite"
    "gorm.io/gorm"
)

type Dome struct {
    gorm.Model
    Location Location `json:"location" gorm:"serializer:json"`
    Title    string   `json:"title" gorm:"type:varchar(100)"`
}

type Location struct {
    X1 int
    Y1 int
    X2 int
    Y2 int
}

func main() {
    db, _ := gorm.Open(sqlite.Open("gorm.db"), &gorm.Config{})

    /*err := db.AutoMigrate(&Dome{})
    if err != nil {
        return
    }*/

        l := Location{}
        l.Y1 = 1
        l.X1 = 2
        l.X2 = 3
        l.Y2 = 4

        d := Dome{}
        d.Title = "test"
        d.Location = l
        db.Create(&d)

        d.Location.Y2 = 6
        db.Save(&d)

        d.Location.X2 = 4
        db.Updates(&d)

    _target := []*Dome{}
    db.Find(&_target)
    for _, t := range _target {
        fmt.Printf("%+v 
", t)
    }
}

I tried like this way and serializer:json worked without an issue.

output:

&{Model:{ID:1 CreatedAt:2022-08-06 14:39:59.184012808 +0530 +0530 UpdatedAt:2022-08-06 14:39:59.184012808 +0530 +0530 DeletedAt:{Time:0001-01-01 00:00:00 +0000 UTC Valid:false}} Location:{X1:2 Y1:1 X2:3 Y2:4} Title:test} 
&{Model:{ID:2 CreatedAt:2022-08-06 14:40:55.666162544 +0530 +0530 UpdatedAt:2022-08-06 14:40:55.677998201 +0530 +0530 DeletedAt:{Time:0001-01-01 00:00:00 +0000 UTC Valid:false}} Location:{X1:2 Y1:1 X2:3 Y2:6} Title:test} 
&{Model:{ID:3 CreatedAt:2022-08-06 14:41:29.361814733 +0530 +0530 UpdatedAt:2022-08-06 14:41:29.367237119 +0530 +0530 DeletedAt:{Time:0001-01-01 00:00:00 +0000 UTC Valid:false}} Location:{X1:2 Y1:1 X2:4 Y2:6} Title:test}

According to documentation you can register serializer and implement how to serialize and deserialize data. https://gorm.io/docs/serializer.html#Register-Serializer

Gorm serialize struct on save/create

1 Answers