轉載自 Laravel-news
1、自增、自減
//常規寫法
$article = Article::find($article_id);
$article->read_count++;
$article->save();
//eloquent寫法-1
$article = Article::find($article_id);
$article->increment('read_count');
//eloquent寫法-2 鏈式寫法
Article::find($article_id)->increment('read_count');
Article::find($article_id)->increment('read_count', 10); // +10
Product::find($produce_id)->decrement('stock'); // -1
複製程式碼2、條件式方法 XorY methods
findOrFail(): 查詢不到的時候直接報錯
$user = User::find($id);
if (!$user) { abort (404); }
//以上程式碼等同於
$user = User::findOrFail($id);
複製程式碼firstOrCreate():使用給定的欄位及其值在資料庫中查詢記錄。如果在資料庫中找不到模型，則將使用第一個引數中的屬性以及可選的第二個引數中的屬性插入記錄
// 通過 name 屬性檢索航班，當結果不存在時建立它...
$flight = App\Flight::firstOrCreate(['name' => 'Flight 10']);
// 通過 name 屬性檢索航班，當結果不存在的時候用 name 屬性和 delayed 屬性去建立它
$flight = App\Flight::firstOrCreate(
['name' => 'Flight 10'], ['delayed' => 1]
);
複製程式碼firstOrNew():用法和firstOrCreate()一樣，但是firstOrNew()只是例項化一個物件，如果需要持久化則需要save()儲存updateOrCreate(): 更新現有模型或建立新模型（如果不存在）,同firstOrCreate()
3、Model類boot()方法
/**
* 基類：新增的時候自動將`uuid`欄位用`Uuid`生成器填充
*/
class BaseModel extends Model
{
public static function boot()
{
parent::boot();
self::creating(function ($model) {
$model->uuid = (string)Uuid::generate();
});
}
}
/**
* 使用者模型：修改的時候設定額外的操作
*/
class User extends BaseModel
{
public static function boot()
{
parent::boot();
static::updating(function($model)
{
// do some logging
// override some property like $model->something = transform($something);
});
}
}
複製程式碼4、關聯新增額外條件並設定排序Relationship with conditions and ordering
//通常的做法，關聯使用者模型
public function users() {
return $this->hasMany('App\User');
}
//關聯已經批准並用`email`排序的使用者模型
public function approvedUsers() {
return $this->hasMany('App\User')->where('approved', 1)->orderBy('email');
}
複製程式碼5、Model類屬性 Model properties: timestamps, appends etc.
class User extends Model {
//經常用到的屬性
protected $table = 'users';
protected $fillable = ['email', 'password']; // which fields can be filled with User::create()
protected $dates = ['created_at', 'deleted_at']; // which fields will be Carbon-ized
protected $appends = ['field1', 'field2']; // additional values returned in JSON
//其他很有用的屬性
protected $primaryKey = 'uuid'; // it doesn't have to be "id"
protected $keyType = 'string'; //設定主鍵欄位型別 default `int`
public $incrementing = false; // and it doesn't even have to be auto-incrementing!
protected $perPage = 25; // Yes, you can override pagination count PER MODEL (default 15)
const CREATED_AT = 'created_at';
const UPDATED_AT = 'updated_at'; // Yes, even those names can be overridden
public $timestamps = false; // or even not used at all
}
複製程式碼6、用find方法查詢多條記錄Find multiple entries
//find常用用法
$user = User::find(1);
//find其實也接收 陣列 為引數
$users = User::find([1,2,3]);
複製程式碼7、whereX魔術方法
//where欄位名：欄位名第一字母大寫
$users = User::whereApproved(1)->get(); //等同於 $users = User::where('approved', 1)->get();
User::whereDate('created_at', date('Y-m-d'));
User::whereDay('created_at', date('d'));
User::whereMonth('created_at', date('m'));
User::whereYear('created_at', date('Y'));
複製程式碼8、Order by relationship
場景：論壇很多帖子
topic，需要按有最新發言post的來排序
//帖子關聯最新的發言
public function latestPost()
{
return $this->hasOne(\App\Post::class)->latest();
}
$users = Topic::with('latestPost')->get()->sortByDesc('latestPost.created_at');
複製程式碼9、Eloquent::when()別再寫那麼多的if-else
//通常的寫法
if (request('filter_by') == 'likes') {
$query->where('likes', '>', request('likes_amount', 0));
}
if (request('filter_by') == 'date') {
$query->orderBy('created_at', request('ordering_rule', 'desc'));
}
//Eloquent::when()寫法
$query = Author::query();
$query->when(request('filter_by') == 'likes', function ($q) {
return $q->where('likes', '>', request('likes_amount', 0));
});
$query->when(request('filter_by') == 'date', function ($q) {
return $q->orderBy('created_at', request('ordering_rule', 'desc'));
});
//可以傳遞引數
$query = User::query();
$query->when(request('role', false), function ($q, $role) {
return $q->where('role_id', $role);
});
$authors = $query->get();
複製程式碼10、BelongsTo Default Models
//blade:如果 author 被刪了就會報錯
{{ $post->author->name }}
//設定 預設Model 避免以上錯誤
public function author()
{
return $this->belongsTo('App\Author')->withDefault([
'name' => 'Guest Author'
]);
}
複製程式碼11、Order by Mutator ： 藉助集合collect->sortBy方法
function getFullNameAttribute()
{
return $this->attributes['first_name'] . ' ' . $this->attributes['last_name'];
}
//錯誤寫法
$clients = Client::orderBy('full_name')->get(); // doesn't work
//正確寫法，藉助collect的sortBy方法
$clients = Client::get()->sortBy('full_name'); // works!
複製程式碼12、Default ordering in global scope
protected static function boot()
{
parent::boot();
// Order by name ASC
static::addGlobalScope('order', function (Builder $builder) {
$builder->orderBy('name', 'asc');
});
}
複製程式碼13、 Raw query methods
// whereRaw
$orders = DB::table('orders')
->whereRaw('price > IF(state = "TX", ?, 100)', [200])
->get();
// havingRaw
Product::groupBy('category_id')->havingRaw('COUNT(*) > 1')->get();
// orderByRaw
User::where('created_at', '>', '2016-01-01')
->orderByRaw('(updated_at - created_at) desc')
->get();
複製程式碼14、Replicate: make a copy of a row
這是複製某條記錄最好的方法
$task = Tasks::find(1);
$newTask = $task->replicate();
$newTask->save();
複製程式碼15、Chunk() method for big tables
Collect集合方法：需要輸出大量記錄的時候用chunk
User::chunk(100, function ($users) {
foreach ($users as $user) {
// ...
}
});
複製程式碼16、Create additional things when creating a model
用
artisan命令生成model的時候一起生成controller -r、migration file
php artisan make:model Company -mcr
複製程式碼17、Override updated_at when saving
save()方法接收額外的引數
$product = Product::find($id);
$product->updated_at = '2019-01-01 10:00:00';
$product->save(['timestamps' => false]);
複製程式碼18、What is the result of an update()?
//返回更新的記錄數
$result = $products->whereNull('category_id')->update(['category_id' => 2]);
複製程式碼19、where引數分組
//... WHERE (gender = 'Male' and age >= 18) or (gender = 'Female' and age >= 65) 的 Eloquent 寫法
$q->where(function ($query) {
$query->where('gender', 'Male')
->where('age', '>=', 18);
})->orWhere(function($query) {
$query->where('gender', 'Female')
->where('age', '>=', 65);
})
複製程式碼20、orWhere with multiple parameters
$q->orWhere(['b' => 2, 'c' => 3]);
複製程式碼