Laravel问答6 Migration评论API

---

• 创建评论Migration
• 创建评论表结构
• 创建评论表模型
• 实现评论API
  • 添加评论API
  • 查看评论API
  • 删除评论API

1. 创建评论Migration

php artisan make:migration create_table_comments --create=comments

2. 创建评论表结构

increments('id');
            $table->timestamps();
            //自定义字段
            $table->text('content')->comment('评论内容');
            $table->unsignedInteger('user_id')->comment('评论人');
            $table->unsignedInteger('question_id')->nullable()->comment('问题编号');//可为空，由于无法确认是针对问题评论
            $table->unsignedInteger('answer_id')->nullable()->comment('回答编号');//可为空，由于无法确认是针对回答评论
            $table->unsignedInteger('reply_to')->nullable()->comment('回复评论');
            //外键关系
            $table->foreign('user_id')->references('id')->on('users');
            $table->foreign('question_id')->references('id')->on('questions');
            $table->foreign('answer_id')->references('id')->on('answers');
            $table->foreign('reply_to')->references('id')->on('comments');

        });
    }
    public function down()
    {
        Schema::dropIfExists('comments');
    }
}

版本2
public function up()
{
    Schema::create('comments', function (Blueprint $table) {
        $table->increments('id');

        $table->text('content')->comment('内容');

        $table->unsignedInteger('user_id')->default('0')->comment('评论人');
        $table->foreign('user_id')->references('id')->on('users');

        $table->unsignedInteger('question_id')->nullable()->comment('问题');
        $table->foreign('question_id')->references('id')->on('questions');

        $table->unsignedInteger('answer_id')->nullable()->comment('回答');
        $table->foreign('answer_id')->references('id')->on('answers');

        $table->unsignedInteger('reply_id')->nullable()->comment('回复评论');
        $table->foreign('reply_id')->references('id')->on('comments');

        $table->timestamps();
    });
}

注意：reply_id 是针对评论而发表的评论，因此外键连接的位置仍然是 comments 表。

php artisan migrate --pretend
php artisan migrate:rollback
php artisan migrate

3. 创建评论表模型

php artisan make:model Model\Comment

namespace App\Model;

use Illuminate\Database\Eloquent\Model;

class Comment extends Model
{
    
}

4.实现评论API

路由文件中提取公共函数

function commentInstance(){
    return new App\Model\Comment;
}

4.1 添加评论API

创建路由

Route::any('/api/comment/add',function(){
    return commentInstance()->add();
});

实现方法

/*添加评论API*/
public function add()
{
    //检查用户是否登录
    if(!userInstance()->isLogin()){
        return ['err'=>1, 'msg'=>'请先登录'];
    }
    //判断是否具有评论内容
    if(!rq('content')){
        return ['err'=>1, 'msg'=>'请先评论'];
    }
    //判断是对问题评论或是对回答评论
    if(!rq('question_id') && !rq('answer_id')){
        return ['err'=>1, 'msg'=>'请针对问题或回答进行评论'];
    }
    //判断是否同时对问题或答案评论
    if(rq('questioin_id') && rq('answer_id')){
        return ['err'=>1, 'msg'=>'请勿针对问题和答案同时评论'];
    }
    //若针对问题评论
    if(rq('question_id')){
        //判断问题是否存在
        $question = questionInstance()->find(rq('question_id'));
        if(!$question){
            return ['err'=>1, 'msg'=>'问题不存在'];
        }
        $this->question_id = rq('question_id');
    }
    //若针对回答评论
    if(rq('answer_id')){
        //判断回答是否存在
        $answer = answerInstance()->find(rq('answer_id'));
        if(!$answer){
            return ['err'=>1, 'msg'=>'回答不存在'];
        }
        $this->answer_id = rq('answer_id');
    }
    //判断是否对自身评论进行回复
    if(rq('reply_to')){
        $target = $this->find(rq('reply_to'));
        if(!$target){
            return ['err'=>1, 'msg'=>'目录评论不存在'];
        }
        //禁止自己回复自己
        if($target->user_id == session('user.id')){
            return ['err'=>1, 'msg'=>'禁止回复自身评论'];
        }
    }
    $this->content = rq('content');
    $this->user_id = session('user.id');
    $this->reply_to = rq('reply_to');
    //插入数据库并返回结果
    return $this->save() ? ['err'=>0,'id'=>$this->id] : ['err'=>1, 'msg'=>'新增失败'];
}

# 版本2
/*API 添加评论*/
public function add()
{
    //判断用户是否登录
    if(!user()->islogin()){
        return ['err'=>1, 'msg'=>'尚未登录'];
    }
    $this->user_id = session('user_id');

    //判断评论内容
    if(!rq('content')){
        return ['err'=>1, 'msg'=>'缺少评论内容'];
    }
    $this->content = rq('content');

    //针对问题或回答评论
    if(!rq('question_id') && !rq('answer_id')){
        return ['err'=>1, 'msg'=>'缺少问题编号或回答编号'];
    }
    if(rq('question_id') && rq('answer_id')){
        return ['err'=>1, 'msg'=>'禁止同时评论问题和回答'];
    }

    //针对问题评论
    if(rq('question_id')){
        //判断问题是否存在
        $question = question()->find(rq('question_id'));
        if(!$question){
            return ['err'=>1,'msg'=>'问题不存在'];
        }
        $this->question_id = rq('question_id');
    }

    //针对回答评论
    if(rq('answer_id')){
        //判断回答是否存在
        $answer = answer()->find(rq('answer_id'));
        if(!$answer){
            return ['err'=>1, 'msg'=>'回答不存在'];
        }
        $this->answer_id = rq('answer_id');
    }

    //针对评论而评论
    if(rq('reply_id')){
        //判断评论是否存在
        $comment = $this->find(rq('reply_id'));
        if(!$comment){
            return ['err'=>1, 'msg'=>'评论不存在'];
        }

        //禁止对自己评论进行评论
        if($comment->user_id == session('user_id')){
            return ['err'=>1, 'msg'=>'禁止自身评论'];
        }

        $this->reply_id = rq('reply_id');
    }
    

    //保存数据
    return $this->save()?['err'=>0,'msg'=>'评论成功','id'=>$this->id]:['err'=>1,'msg'=>'评论失败'];

}

4.2 查看评论API

创建路由

Route::any('/api/comment/read',function(){
    return commentInstance()->read();
});

实现方法

public function read()
{
    //判断参数是否存在
    if(!rq('question_id') && !rq('answer_id')){
        return ['err'=>1, 'msg'=>'参数错误'];
    }
    //根据问题查看评论
    if(rq('question_id')){
        //判断问题是否存在
        $question = questionInstance()->find(rq('question_id'));
        if(!$question){
            return ['err'=>1, 'msg'=>'问题不存在'];
        }
        //获取问题下所有评论
        $data = $this->where('question_id',rq('question_id'))->get();

    }
    //根据回答查看评论
    if(rq('answer_id')){
        //判断回答是否存在
        $answer = answerInstance()->find(rq('answer_id'));
        if(!$answer){
            return ['err'=>1, 'msg'=>'回答不存在'];
        }
        //获取回答下所有评论
        $data = $this->where('answer_id',rq('answer_id'))->get();
    }
    return $data->isEmpty() ? ['err'=>1, 'msg'=>'暂无评论'] : ['err'=>0,'data'=>$data->keyBy('id')];
}

# 版本2
/*API 查看评论*/
public function read()
{
    //判断参数
    if(!rq('question_id') && !rq('answer_id')){
        return ['err'=>1, 'msg'=>'缺少问题编号或回答编号'];
    }

    //查看问题的评论
    if(rq('question_id')){
        //判断问题是否存在
       $question = question()->find(rq('question_id'));
       if(!$question){
           return ['err'=>1, 'msg'=>'问题不存在'];
       }
        //获取问题下所有评论
       $comment = $this->where('question_id',rq('question_id'));
    }

    //查看回答下的评论
    if(rq('answer_id')){
        //判断回答是否存在
        $answer = answer()->find(rq('answer_id'));
        if(!$answer){
            return ['err'=>1, 'msg'=>'回答不存在'];
        }
        //获取回答下所有评论
        $comment = $this->where('answer_id', rq('answer_id'));
    }

    $data = $comment->get()->keyBy('id');
    //返回评论
    return $data->isEmpty() ? ['err'=>1, 'msg'=>'暂无评论'] : ['err'=>0, 'data'=>$data];
}

4.3 删除评论API

创建路由

Route::any('/api/comment/remove',function(){
    return commentInstance()->remove();
});

实现方法

/*删除评论API*/
public function remove()
{
    //检查用户是否登录
    if(!userInstance()->isLogin()){
        return ['err'=>1, 'msg'=>'请先登录'];
    }
    //根据评论编号删除
    if(!rq('id')){
        return ['err'=>1, 'msg'=>'参数错误'];
    }
    //判断评论是否存在
    $comment = $this->find(rq('id'));
    if(!$comment){
        return ['err'=>1, 'msg'=>'评论不存在'];
    }
    //判断是否为本人评论
    if($comment->user_id != session('user.id')){
        return ['err'=>1, 'msg'=>'权限错误'];
    }
    //删除所有回复过评论的评论
    $this->where('reply_to',rq('id'))->delete();
    //删除评论
    return $comment->delete() ? ['err'=>0, 'msg'=>'删除成功'] : ['err'=>1, 'msg'=>'删除失败'];
}

# 版本2
/*API 删除评论*/
public function del()
{
    //判断用户是否登录
    if(!user()->islogin()){
        return ['err'=>1, 'msg'=>'尚未登录'];
    }

    //判断评论编号
    if(!rq('id')){
        return ['err'=>1, 'msg'=>'缺少评论编号'];
    }

    //判断评论是否存在
    $comment = $this->find(rq('id'));
    if(!$comment){
        return ['err'=>1, 'msg'=>'评论不存在'];
    }

    //自身可删除
    if($comment->user_id != session('user_id')){
        return ['err'=>1, 'msg'=>'权限不足'];
    }

    //删除评论下的回复
    $this->where('reply_id',rq('id'))->delete();

    //删除评论
    return $comment->delete()?['err'=>0,'msg'=>'删除成功']:['err'=>1,'msg'=>'删除失败'];
}