Laravel Eloquent where and order conditions only if needed

Question

请看下面的代码。这段代码是我用 Codeigniter 写的。我需要强调的是，只有在设置了 post 请求的情况下，条件和订单条件才有效。否则我只是 select * from student.

Codeigniter 代码

$this->db->select('*');
$this->db->from('student');
if($this->input->post('first_name') != NULL){
    $first_name = $this->input->post('first_name');
    $this->db->where('first_name', $first_name);
}

if($this->input->post('last_name') != NULL){
    $last_name= $this->input->post('last_name');
    $this->db->where('last_name', $last_name);
}

if($this->input->post('order_by') != NULL){
    $order_by= $this->input->post('order_by');
    $this->db->order_by($order_by);
}

$query = $this->db->get();

Laravel代码

我将对 laravel 做同样的事情。

$first_name = $request->input('first_name');
$last_name = $request->input('last_name');
$order_by = $request->input('$order_by');

$students = Student::orderBy($order_by)
      ->where('first_name',$first_name)
      ->where('last_name',$last_name);
      ->paginate(10);

我能够运行以上代码。该代码在所有 post 请求时有效。

但是如果没有 first_name post 请求我需要删除 ->where('first_name',$first_name).

如果没有order_bypost请求，我需要删除orderBy($order_by).

如何使用上面的 Laravel 代码。

Answer 1

同样的方法：

$first_name = $request->input('first_name');
$last_name = $request->input('last_name');
$order_by = $request->input('$order_by');

$query = Student::orderBy($order_by);
if ($first_name) {
    $query->where('first_name',$first_name);
}

if ($last_name) {
    $query->where('last_name',$last_name);
}

$students = $query->paginate(10);
return $students;

Answer 2

你可以像这样使用，

$students = Student::latest();

if (isset($request->input('order_by'))) {
    $students->orderBy($order_by)
}
if (isset($request->input('first_name'))) {
          $students->where('first_name',$first_name);
}
if (isset($request->input('last_name'))) {
          $students->where('last_name',$last_name);
}
$students->paginate(10);

Answer 3

你可以这样做，

$first_name = $request->input('first_name');
$last_name = $request->input('last_name');
$order_by = $request->input('order_by');

$query = DB::table('student');

if($request->first_name){
    $query->where('first_name',$first_name)
}

if($request->last_name){
    $query->where('last_name',$last_name);
}

if($request->order_by){
    $query->orderBy($order_by);
}

$students = $query->paginate(10);

希望你明白。

Answer 4

$query = Student::where('last_name',$last_name);
if ($request->has('first_name')) {
    $query->where('first_name',$first_name);
}
if ($request->has('order_by')) {
    $query->orderBy($order_by);
}

$students = $query->paginate(10);

Answer 5

一种方法是检查名称是否已设置，然后将其添加到查询构建器中，如下所示：

$first_name = $request->input('first_name');
...

$students = Student::orderBy($order_by)
if ($first_name) {
    $students->where('first_name',$first_name)
}

$students->paginate(10);

但是你可以清理它！由于 Laravel 5.2.27 您可以执行以下操作：

$students = Student::orderBy($order_by)
->when($request->input('first_name'), function($query) use ($request){
    return $query->where('first_name', $request->input('first_name'));
})
->paginate(10);

为了使其更具可读性，您可以为 if 语句使用自定义宏：

$students = Student::orderBy($order_by)
->if($request->input('first_name'), 'first_name', '=', $request->input('first_name'))
->paginate(10);

和宏：

use Illuminate\Database\Query\Builder;

Builder::macro('if', function ($condition, $column, $operator, $value) {
    if ($condition) {
        return $this->where($column, $operator, $value);
    }

    return $this;
});

来源：https://themsaid.com/laravel-query-conditions-20160425 希望对您有所帮助！

Laravel Eloquent where and order conditions only if needed

Laravel Eloquent where and order conditions only if needed

php

laravel

laravel-5

laravel-eloquent