php - SQLSTATE[23000] : Integrity constraint violation: 19 NOT NULL constraint failed:

Question

尝试在 Laravel 上创建一个待办事项列表应用程序，但是当我尝试单击按钮创建一个新的待办事项列表时，出现此错误:

SQLSTATE[23000]: Integrity constraint violation: 19 NOT NULL constraint failed: tasks.description (SQL: insert into "tasks" ("description", "user_id", "updated_at", "created_at") values (, 1, 2017-10-09 03:28:35, 2017-10-09 03:28:35))

这是我的 Controller :

<?php

namespace App;

use Illuminate\Notifications\Notifiable;
use Illuminate\Foundation\Auth\User as Authenticatable;

class User extends Authenticatable
{
    use Notifiable;

    /**
     * The attributes that are mass assignable.
     *
     * @var array
     */

    public function tasks()
    {
        return $this->hasMany(Task::class);
    }

    protected $fillable = [
        'name', 'email', 'password',
    ];

    /**
     * The attributes that should be hidden for arrays.
     *
     * @var array
     */
    protected $hidden = [
        'password', 'remember_token',
    ];
}

这是我的任务模型:

命名空间应用；

使用 Illuminate\Database\Eloquent\Model；

class Task extends Model
{
    public function user()
    {
        return $this->belongsTo(User::class);
    }

}

这是用户模型:

<?php

namespace App;

use Illuminate\Notifications\Notifiable;
use Illuminate\Foundation\Auth\User as Authenticatable;

class User extends Authenticatable
{
    use Notifiable;

    /**
     * The attributes that are mass assignable.
     *
     * @var array
     */

    public function tasks()
    {
        return $this->hasMany(Task::class);
    }

    protected $fillable = [
        'name', 'email', 'password',
    ];

    /**
     * The attributes that should be hidden for arrays.
     *
     * @var array
     */
    protected $hidden = [
        'password', 'remember_token',
    ];
}

这是 View :

@extends('layouts.app')

@section('content')
    <div class="container">
        @if (Auth::check())
            <h2>Tasks List</h2>
            <a href="/task" class="btn btn-primary">Add new Task</a>
            <table class="table">
                <thead><tr>
                    <th colspan="2">Tasks</th>
                </tr>
                </thead>
                <tbody>@foreach($user->tasks as $task)
                    <tr>
                        <td>
                            {{$task->description}}
                        </td>
                        <td>

                            <form action="/task/{{$task->id}}">
                                <button type="submit" name="edit" class="btn btn-primary">Edit</button>
                                <button type="submit" name="delete" formmethod="POST" class="btn btn-danger">Delete</button>
                                {{ csrf_field() }}
                            </form>
                        </td>
                    </tr>


                @endforeach</tbody>
            </table>
        @else
            <h3>You need to log in. <a href="/login">Click here to login</a></h3>
        @endif

    </div>
@endsection

似乎无法找出问题，谷歌似乎也没有想法。

Answer 1

您得到的错误意味着表中有些列没有空约束，您正在插入/更新空值。

更正它:

1) 为该列提供一个非空值并添加到您的任务模型代码段中:

protected $fillable = [
    'description'];

或

2) 通过编写以下内容使迁移文件中表中的列可为空:

$table->('description')->nullable();

从它的任务模型中删除您(在您的表中)可以为空的列名。

=> 通过删除所有表清空 phpmyadmin 中的数据库。

=> 运行命令:php artisan migrate

=> 尝试再次执行您的操作。