unsupported data type: &[], a model can't be migrated

[raliqala]

Good day

Am sorry for asking this here, it seem this error is from jwt so gorm can't migrate the model.

System specs

• go latest
• gofiber
• windows 11
• postgres

Am trying to AutoMigrate a claims model but i get the follwing error

My Model

package models

import (
	"github.com/golang-jwt/jwt/v4"
	"github.com/google/uuid"
)

type Claims struct {
	jwt.RegisteredClaims
	ID uuid.UUID `gorm:"type:uuid;default:uuid_generate_v4()"`
}

The ERROR i get when i run the project

Running the migrations...

2021/12/30 13:17:56 ←[35mC:/personal/projects/uni-blog/src/database/connect.go:43
←[0m←[31m[error] ←[0munsupported data type: &[]

2021/12/30 13:17:56 ←[35mC:/personal/projects/uni-blog/src/database/connect.go:43
←[0m←[31m[error] ←[0mfailed to parse value &models.Claims{RegisteredClaims:jwt.RegisteredClaims{Issuer:"", Subject:"", Audience:jwt.ClaimStrings(nil), ExpiresAt:<nil>, NotBefore:<nil>, IssuedAt:<nil>, ID:""}, ID:uuid.UUID{0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}}, got error unsupported data type: &[]

2021/12/30 13:17:56 ←[35mC:/Users/raliq/go/pkg/mod/gorm.io/driver/[email protected]/migrator.go:192
←[0m←[31m[error] ←[0munsupported data type: &[]

2021/12/30 13:17:56 ←[35mC:/Users/raliq/go/pkg/mod/gorm.io/driver/[email protected]/migrator.go:167
←[0m←[31m[error] ←[0munsupported data type: &[]

2021/12/30 13:17:56 ←[35mC:/Users/raliq/go/pkg/mod/gorm.io/driver/[email protected]/migrator.go:167
←[0m←[31m[error] ←[0mfailed to parse value &models.Claims{RegisteredClaims:jwt.RegisteredClaims{Issuer:"", Subject:"", Audience:jwt.ClaimStrings(nil), ExpiresAt:<nil>, NotBefore:<nil>, IssuedAt:<nil>, ID:""}, ID:uuid.UUID{0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}}, got error unsupported data type: &[]

2021/12/30 13:17:56 ←[35mC:/Users/raliq/go/pkg/mod/gorm.io/driver/[email protected]/migrator.go:167
←[0m←[31m[error] ←[0munsupported data type: &[]
Sorry couldn't migrate'...
Database connection was successful...

it was working when i was using jwt.StandardClaims after i changed its not working any more, it migrates the user model first then it gets stuck on the claims model

db connection code
var DB *gorm.DB

func ConnectPg() {
	p := config.Config("DB_PORT")
	port, err := strconv.Atoi(p)
	// port, err := strconv.ParseUint(p, 10, 32)
	if err != nil {
		log.Println("Sorry db port error: ", err)
	}

	// connection url to DB
	dns := fmt.Sprintf("host=%s port=%d user=%s password=%s dbname=%s sslmode=disable", config.Config("DB_HOST"), port, config.Config("DB_USER"), config.Config("DB_PASSWORD"), config.Config("DB_NAME"))

	// connect to DB
	var dbErr error
	DB, dbErr = gorm.Open(postgres.Open(dns), &gorm.Config{})

	if dbErr != nil {
		panic("failed to connect to database..")
	}

	fmt.Println("Running the migrations...")

	if migrateErr := DB.AutoMigrate(&models.User{}, &models.Claims{}, &models.Permission{}, &models.Role{}, &models.RolePermission{}, &models.SessionLog{}); migrateErr != nil {
		fmt.Println("Sorry couldn't migrate'...")
	}

	fmt.Println("Database connection was successful...")
}

Please help
Thanks in advance

[oxisto]

I was able to reproduce this. This is tricky, the error is produced because of the new type jwt.ClaimsStrings, which is necessary because aud can either be a string or an array of strings (according to the JWT spec). This was incorrectly handled in our previous claims struct. The problem is, that the postgres driver cannot handle a structure which contains an array on its own. What I recommend would be to store the claims as a string rather than a struct in the database. Alternatively, there might be a way to configure/override the way gorm migrates the model using a custom function.

Beware, that storing any kind of credentials (and claims are credentials) on a database or other "persistent" storage is not a good idea in general, but that of course depends on your use case.

[raliqala]

Thank you , and thanks for the advice too thank you