Laravel

Question

我正在尝试编写一些代码，显示 Laravel 中数据库中的数据。但是我有两个 table 值通过外键相互链接，当我尝试在我的页面上显示它时，它只显示 ID 而不是实际名称。我在另一个 Whosebug 问题中看到您应该在您的模型中定义 table 数据值，但这不起作用或者我做错了。有人可以帮我解决这个问题吗？ :)

型号Planet.php:

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class Planet extends Model
{
    public function solar()
    {
    return $this->belongsTo(SolarSystems::class, 'id');
    }
}

型号SolarSystems.php:

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class SolarSystems extends Model
{
    public function planet()
    {
        return $this->belongsTo(Planet::class, 'solar_systems_id');
    }
}

PlanetController.php:

<?php

namespace App\Http\Controllers;
use Illuminate\Http\Request;
use App\Models\Planet;
use App\Models\SolarSystems;

class PlanetController extends Controller
{
    public function index()
    {
        $planets = Planet::all();
        $solar = SolarSystems::all();

        return view('welcome', ['planets'=>$planets]);
    }
    public function show($planeet)
    {
        $planets = Planet::all();
        $solar = SolarSystems::all();
    
        $planets = collect($planets)->where('name', $planeet);
        return view('welcome', ['planets' => $planets]);
    }
}

welcome.blade.php:

<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8">
        <meta name="viewport" content="width=device-width, initial-scale=1">
        <title>Laravel</title>
        <link href="https://fonts.googleapis.com/css2?family=Nunito:wght@400;600;700&display=swap" rel="stylesheet">
        <style>
            body {
                font-family: 'Nunito', sans-serif;
            }
        </style>
    </head>
    <body>

@foreach ($planets as $planeten)
    <ul>
        <li>{{ ucfirst($planeten->name) }}</li>
        <p>{{ ucfirst($planeten->description) }}</p>
        <p>{{ ucfirst($planeten->solar_systems_id) }}
    </ul>
@endforeach
    </body>
</html>

import.sql:

CREATE DATABASE laravel;
USE laravel;
CREATE TABLE planets (
    id int(11) AUTO_INCREMENT,
    name text,
    description text,
    size_in_km int(11),
    solar_systems_id int(11),
    PRIMARY KEY (id)
);

CREATE TABLE solar_systems (
    id int(11) AUTO_INCREMENT,
    name text,
    age_in_years int(11),
    PRIMARY KEY (id)
);

INSERT INTO planets (name, description, size_in_km, solar_systems_id)
VALUES ('mars', 'Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, being larger than only Mercury.', 3389, 1);

INSERT INTO planets (name, description, size_in_km, solar_systems_id)
VALUES ('venus', 'Venus is the second planet from the Sun. It is named after the Roman goddess of love and beauty.', 6051, 1);

INSERT INTO planets (name, description, size_in_km, solar_systems_id)
VALUES ('earth', 'Our home planet is the third planet from the Sun, and the only place we know of so far thats inhabited by living things.', 6371, 1);

INSERT INTO solar_systems (name, age_in_years)
VALUES ('The Milky Way', 1360000000);

这是我现在得到的，但它需要说的不是“1”：'The Milky Way'

Answer 1

替换此行

<p>{{ ucfirst($planeten->solar_systems_id) }}

用这条线

<p>{{ ucfirst($planeten->solar()->name) }}</p>

Answer 2

只需替换这一行

{{ ucfirst($planeten->solar_systems_id) }} 

with this line 

{{ ucfirst($planeten->solar->name) }}

因为需要从关系中获取名字

Answer 3

您的代码几乎没有问题；

关系

你有 1-N 关系，一个行星属于一个太阳系，一个太阳系有许多行星。

Planet.php

public function solar()
{
    return $this->belongsTo(SolarSystems::class, 'solar_systems_id');
}

SolarSystems.php

public function planets()
{
    return $this->hasMany(Planet::class, 'solar_systems_id');
}

控制器

PlanetController.php

public function show($planeet)
{
    $planets = Planet
              ::with('solar')
              ->where('name', $planeet)
              ->get();
       
    return view('welcome', ['planets' => $planets]);
}

你看到了吗，我正在使用 with 和 where 来优化查询。

with 将预加载关系：well explained in the documentation
where 将向数据库查询添加条件，这将比集合更有效地执行。 Usage

查看

既然已经加载了eager loading的关系，就可以直接访问星球的模型了。

 <p>{{ ucfirst($planeten->solar->name) }}

Laravel - 显示名称而不是 id

Laravel - Show name instead of id

php

foreach

laravel-blade

laravel-models

关系

控制器

查看