laravel - 完整性约束违规 : 1052 Column 'updated_at' in field list is ambiguous

Question

App\User Model 文件内容:-

<?php

namespace App;

use Illuminate\Contracts\Auth\MustVerifyEmail;
use Tymon\JWTAuth\Contracts\JWTSubject;
use Illuminate\Notifications\Notifiable;
use Illuminate\Foundation\Auth\User as Authenticatable;

class User extends Authenticatable implements JWTSubject
{
    use Notifiable;

    /**
     * The attributes that are mass assignable.
     *
     * @var array
     */
    protected $fillable = [
        'name', 'email', 'password',
    ];

    public function khatmas()
    {
        return $this->hasMany('App\Khatma');
        
    }

    public function messages()
    {
        return $this->hasManyThrough('App\KhatmaRead','App\Khatma')
        ->select('reader_name','message','updated_at')
        ->where('message','!=',NULL);
    }

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

    /**
     * The attributes that should be cast to native types.
     *
     * @var array
     */
    protected $casts = [
        'email_verified_at' => 'datetime',
    ];

     public function getJWTIdentifier()
    {
        return $this->getKey();
    }

    /**
     * Return a key value array, containing any custom claims to be added to the JWT.
     *
     * @return array
     */
    public function getJWTCustomClaims()
    {
        return [];
    }
}

khatma_reads 迁移文件:-

    $table->bigIncrements('id');
    $table->unsignedBigInteger('khatma_id');
    $table->foreign('khatma_id')->references('id')->on('khatmas')->onDelete('cascade');
    $table->string('reader_name')->nullable();
    $table->longText('message')->nullable();
    $table->timestamps();

在 user->message() 方法中，当我将列“updated_at”或“created_at”放在 ->select 方法上时出现错误:-

"SQLSTATE[23000]: Integrity constraint violation: 1052 Column 'updated_at' in field list is ambiguous (SQL: select `reader_name`, `message`, `updated_at`, `khatmas`.`user_id` as `laravel_through_key` from `khatma_reads` inner join `khatmas` on `khatmas`.`id` = `khatma_reads`.`khatma_id` where `message` is not null and `khatmas`.`user_id` in (1))"

当我从查询构建器中完全删除 ->select() 方法时，我得到了所有列的响应，包括 created_at 和 updated_at 列。

我该如何解决这个问题？

Answer 1

那是因为你的 KhatmaRead 和 Khatma 模型有 update_at 列，这里:

->select('reader_name','message','updated_at')

您没有指定要从哪个表中获取该列，并且它是模棱两可的。你应该这样做:

->select('reader_name','message','khatma_reads.updated_at')