当我尝试从PHP对象/数组返回值时，出现500错误。 但是可以返回所有对象

Question

I'm trying to create a simple application in Laravel that sends and gets comments from the database.

I'm using both PHP and JS with AJAX. But when I try to get the full comment object:

PHP

    public function UpdateComment(Request $request){
        $id = $request->id;
        $jsonCode = DB::table('comments')->where('id', $id)->get();
        $comment = json_decode($jsonCode);
        return $comment
    }

Works well:

[{…}]
  0:
   author_id: 6
   comment_date: "2018-09-15 09:53:01"
   comment_text: "23423434234"
   history: ""
   id: 60
   last_update: "2018-09-15 00:00:00"
  >proto__: Object
  length: 1
>proto__: Array(0)

This is exactly what I expected to see, the full PHP object. But when I try to return or simply use a single attribute of this same object, I got a 500 error...

return $comment->id;

.

POST http://laravelhost/update-comment 500 (Internal Server Error)

I'm a beginner in PHP, so it should be a very simple error.

Answer 1

Try this:

public function UpdateComment(Request $request){
    $id = $request->id;
    $record = DB::table('comments')->where('id', $id)->get();
    return $record;
}

You don't need to json_decode() the return value of DB::table()... call.

Answer 2

To retrieve a single row you should use first() instead of get()

$comment = DB::table('comments')->where('id', $id)->first();
echo $comment->id;

https://laravel.com/docs/5.7/queries

Answer 3

You are getting error 500 because json_decode() returns an array, not an object. So to access your data use array syntax, instead of object operator:

return $comment['id']

Answer 4

You can either use

$comment = DB::table('comments')->where('id', $id)->first();
return $comment->id;

or

$comment = DB::table('comments')->where('id', $id)->get();
return $comment[0]->id;

If you are using json_decode after fetching data, object will converted to array. So, you have to use $arrayname['keyname'] for fetching data.