Gorm read only field after create

Question

I need to make one of the property of model as read only after create. My code in working but when I try to update It will not throw any error.

Could you please help me in how to get error when we try to Update?

package main

import (
    "fmt"

    "gorm.io/gorm"
)

type Product struct {
    gorm.Model
    ProductID int    `gorm:"primaryKey"`
    Code      string `gorm:"->;<-:create"`
    Price     uint
}

// TestSuite is code to all tests, independent of database
func TestSuite(db *gorm.DB) { // Migrate the schema
    db.AutoMigrate(&Product{})
    // Create
    db.Create(&Product{Code: "D4222", Price: 1000, ProductID: 3})
    // Read
    var product Product
    db.First(&product, "product_id = ?", 3) // find product with product_id 2
    fmt.Println("Product Code After Creation: ", product.Code)
    fmt.Println("Product Price After Creation: ", product.Price)

    //Update
    err := db.Model(&product).Where("product_id = ?", 3).Updates(Product{Price: 400, Code: "F42"}).Error
    if err != nil {
        fmt.Println(err)
    }
    // Read after update
    var updateProd Product
    db.First(&updateProd, "product_id = ?", 3) // find product with product_id 2
    fmt.Println("Product Code After Update: ", updateProd.Code)
    fmt.Println("Product Price After Update: ", updateProd.Price)

    // Delete - delete product
    db.Unscoped().Delete(&updateProd, 3)
}

Output:
Product Code After Creation: D4222
Product Price After Creation: 1000
Product Code After Update: D4222
Product Price After Update: 400

user_16806783 · Answer

if your table not created you don't have any problem

if your table created and you wanna to make two of the property of model as read only following below:

type Test struct {
       EnvID     string      `json:"env_id" gorm:"->"`                                                                                       
       PartID    string      `json:"part_id" gorm:"index:depl_part;unique;priority:3;->"`
}

then you must be to run following code

err := Client.AutoMigrate(&Test{})

now EnvID and PartID are READ-ONLY until you delete -> from GORM and run top code.

Gorm read only field after create

1 Answers