Golang - Html Template : How do I create a Nav-item - Submenu? I couldn't find how to do it

I'm trying to switch from PHP to GO, but I'm stuck at one point, I ask for your help.

I have a table called Menu in the database. Here, menuid equal to 0 becomes the main menu. Those not equal to 0 depend on the written menuid. I want to draw the sub menu it is dependent on, but I can't do it, I'm stuck.

Table > Menu

html

Output > Instead of adding the sub menus one after the other, it adds each of them side by side and as a separate menu.

My PHP Func.

PHP Output (working)

Instead of adding the sub menu one after the other , it adds each of them side by side and as a separate menu . I couldn't find how to do it.

I solved my problem.

I implemented a structure like below. Anyone who needs it can copy it from here.

package main

import (
    "html/template"
    "log"

    "github.com/gofiber/fiber/v2"
    "gorm.io/driver/sqlite"
    "gorm.io/gorm"
)

type MenuItem struct {
    gorm.Model
    Title    string
    ParentID int
    URL      string
    SubMenu  []MenuItem `gorm:"-"`
}

var db *gorm.DB

func main() {
    app := fiber.New()

    var err error
    db, err = gorm.Open(sqlite.Open("menu.db"), &gorm.Config{})
    if err != nil {
        log.Fatal(err)
    }

    db.AutoMigrate(&MenuItem{})

    app.Get("/", func(c *fiber.Ctx) error {
        menuItems := []MenuItem{}
        db.Where("parent_id = ?", 0).Find(&menuItems)
        for i := range menuItems {
            subMenuItems := []MenuItem{}
            db.Where("parent_id = ?", menuItems[i].ID).Find(&subMenuItems)
            menuItems[i].SubMenu = subMenuItems
        }
        return c.Render("index", fiber.Map{"MenuItems": menuItems})
    })

    app.Static("/static", "./static")

    app.Listen(":8080")
}

html

<nav>
    <ul>
        {{ range $index, $item := .MenuItems }}
            <li><a href="{{ $item.URL }}">{{ $item.Title }}</a></li>
            {{ if $item.SubMenu }}
                <ul>
                    {{ range $subIndex, $subItem := $item.SubMenu }}
                        <li><a href="{{ $subItem.URL }}">{{ $subItem.Title }}</a></li>
                    {{ end }}
                </ul>
            {{ end }}
        {{ end }}
    </ul>
</nav>