How to get SQL statements to randomly fetch 10 data in Laravel

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First, attach the MySQL official documentation excerpt and Link:

ORDER BY RAND()Combined with are LIMIT useful for selecting a random sample from a set of rows:

Simple translation of the above (for students who are not good at English):

ORDER BY RAND()And LIMIT used together, can be used to select a random part from multiple rows of results

mysql> SELECT * FROM table1, table2 WHERE a=b AND c
  
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其次，使用Laravel Eloquent的查询器（query builder），需要用到DB（Facade）进行原生查询：

因为不了解你的查询的上下文，所以这里用假想的Post模型进行说明

$post = Post::where('category_id', $category_id) ->orderBy(\DB::raw('RAND()')) ->take(10) ->get();

解释：

1. Eloquent的orderBy方法只支持第二个参数为ASC和DESC，因此，这里需要调用DB::raw方法来实现原生查询

2. 另外，还可以使用orderByRaw('RAND()')，效果等同

3. 限制结果数目，要用Eloquent的take方法，相当与SQL的LIMIT

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