php - 我可以在 Eloquent 中使用 INNER JOIN 而不是两个查询来查询关系吗？

Question

我可以写这样的东西：

$post = Post::join(['author'])->find($postId);
$authorName = $post->author->name;

只生成一个带有内部连接的选择（没有 2 个选择）并且不使用 DB 查询生成器

SELECT
  post.*, 
  author.*
FROM post
  INNER JOIN author 
    ON author.id = post.author_id
WHERE post.id = ?

Answer 1

You can do it in Eloquent using the join method:

$post = Post::join('author', function($join)
    {
        $join->on('author.id', '=', 'post.author_id');
    })
    ->where('post.id', '=', $postId)
    ->select('post.*', 'author.*')
    ->first();

Please note that your results in $post will be an object where their attributes will correspond to the result set, if two columns has the same name it will be merged. This happen when using:

->select('post.*', 'author.*')

To avoid this, you should create alias to those columns in the select clause as shown below:

->select('post.id AS post_id', 'author.id AS author_id')

Answer 2

尝试

Post::join('author',function($join){
  $join->on('author.id','=','post.author_id');
})->where('post.id','=',$postId)->select('post.*','author.*');