[relation] #LaravelT

relation.php

// belongs to - one to one - one to many - many to mayn

class PostModel extends Model
{
    protected $fillable =['title','des','user_id'];
    public function user(){
        return $this->belongsTo(User::class);
//        return User::findOrFail($this->user_id);
    }
}

class User extends Model
{
    protected $fillable = [
        'name', 'email', 'password',
    ];
    public function posts(){
        return $this->hasMany(PostModel::class);// relation
//        return PostModel::where('user_id',$this->id)->get();
    }
}

// for user migration
public function up()
{
  Schema::create('users', function (Blueprint $table) {
    $table->increments('id');
    $table->string('name');
    $table->string('email')->unique();
    $table->timestamp('email_verified_at')->nullable();
    $table->string('password');
    $table->rememberToken();
    $table->timestamps();

  });
}

// for post migration
public function up()
{
  Schema::create('post_models', function (Blueprint $table) {
    $table->bigIncrements('id');
    $table->text('title');
    $table->integer('user_id')->unsigned();
    $table->text('des');
    $table->timestamps();
    $table->foreign('user_id')->references('id')->on('users')->onDelete('cascade');
  });
}

// IMPORTANT
 return $posts->user; // not user()

 return $user->posts;  // not posts



// One to One ----------------------------
//each user has one profile
    $user=\App\User::find(3);
    $user_profile=$user->profile;


class User extends Authenticatable
{
    use Notifiable;
    protected $fillable = ['name', 'email', 'password',];
    protected $hidden = ['password', 'remember_token',];
    protected $casts = [ 'email_verified_at' => 'datetime',];

    public function profile(){
        return $this->hasOne(ProfileModel::class);// relation
//        return ProfileModel::where('user_id',$this->id)->get();
    }
}
// One to Many----------------------------------------------------------------
// each user has many post
    $user=\App\User::find(3);
    $user_posts=$user->posts;// if use posts() insted of posts its return relatio

    $custom_post=$user->posts()->where('updated_at','>','2018-10-07 15:06:32')->get()-toArray();
	$last_posts= $user->LastPosts(90)->get()->toArray();
	$user_with_post=\app\User::has(posts)->get();
	$user_with_post_more_than_5=\app\User::has(posts,'>',5)->get();

	$query_with_function=User::wherehas('posts',function($query){
      $query->where('title','like','%hello%)
    })-get();
    
    $query_with_function=User::doesntHave('posts')-get();
    
    $query_with_function=User::whereDoesntHave('posts',function($query){
      $query->where('title','like','%hello%)
    })-get();

	$user_all=User::get()->toArray();
	$user_all=User::with('profile')->get();
	$user_all=User::with('profile:user_id,age,email,bio')->get(); //user_id is key

	$user_all=User::withCount('posts as post_count')->toArray();// get use with post_count
	$user_all=User::withCount(['posts as post_count','tweets as tweet_count'])->toArray();// get use with post_count


class User extends Authenticatable
{
    use Notifiable;
    protected $fillable = ['name', 'email', 'password',];
    protected $hidden = ['password', 'remember_token',];
    protected $casts = [ 'email_verified_at' => 'datetime',];

    public function posts(){
        return $this->hasMany(PostModel::class);// relation
//        return PostModel::where('user_id',$this->id)->get();
    }
  
  	public function scopeLastPosts($query,$minuts=60){
    	return $this->posts()->where('created_at','>',Carbon::now()->subMinutes($minuts));
    }
  
 
  
  
}

// for get user from each post------------------------------------
class PostModel extends Model
{
    public function user(){
    return $this->belongsTo(User::class);
    }
}

 $user=\App\User::find(3);
 $user_posts=$user->posts;
 $first_post=$user_posts[0];
 $user_own_post=$first_post->user;
 $user_own_post_email=$first_post->user->value('email');

//Many to Many----------------------------------
// every post can have many tag , every tag can have many post
// this need a new table
// posts_table , tags_table , post_tag_table

php artisan make:migration create_post_tags_table --create=post_tags
// becareful : laravel name like: table1_table2

$table->unsignInteger('post_id');
$table->unsignInteger('tag_id');
$table->primary(['post_id','tag_id']); // very importan : every post can include just a tag (once)
$table->forign('post_id')->refrencs('id')->on('posts');
$table->forign('tag_id')->refrencs('id')->on('tags');

// we do not need any model for this migration

// add your tags in table tags

class PostModel extends Model
{
  
  public function tags(){
    
    return $this->belognsToMany(Tag::class); // if you not named like laravel (line67) return $this->belognsToMany(Tag::class,'post_tags'); line(58)
    
    
    //$tag_ids = \DB::table('post_tag')->where('post_id',$this->id)->pluck('tag_id')->toArray(); // give all tag id seted to post
	//$tags=Tag::whereIn('id',$tag_ids');
	//return $tags;
  }
    
}

class TagModel extends Model
{
      return $this->belognsToMany(Post::class); // if you not named like laravel (line67) return $this->belognsToMany(Tag::class,'post_tags'); line(58)
    
}



$post=Post::find(3);
$tags=$post->tags;


$tag=Tag::find(1);
$posts=$tag->posts();














//easy way: without relation
$post=Post::find(1);
$tag_ids = DB::table('post_tag')->where('post_id',$post->id)->pluck('tag_id')->toArray(); // give all tag id seted to post
$tags=Tag::whereIn('id',$tag_ids');