Laravel - Union + Paginate at the same time?

Question

Brief:

I am trying to union 2 tables recipes and posts then add ->paginate(5) to the queries.

But for some reason I get this error:

Cardinality violation: 1222 The used SELECT statements have a different number of columns (SQL: (select count(*) as aggregate from posts

Code:

$recipes = DB::table("recipes")->select("id", "title", "user_id", "description", "created_at")
                    ->where("user_id", "=", $id);

$items = DB::table("posts")->select("id", "title", "user_id", "content", "created_at")
                ->where("user_id", "=", $id)
                ->union($recipes)
                ->paginate(5)->get();

Am i doing something wrong?

Without ->paginate(5) the query works fine.

Solution 1

You're right, pagination cause problem. Right now, you can create a view and query the view instead of the actual tables, or create your Paginator manually:

$page = Input::get('page', 1);
$paginate = 5;

$recipes = DB::table("recipes")->select("id", "title", "user_id", "description", "created_at")
            ->where("user_id", "=", $id);
$items = DB::table("posts")->select("id", "title", "user_id", "content", "created_at")
            ->where("user_id", "=", $id)
            ->union($recipes)
            ->get();

$slice = array_slice($items->toArray(), $paginate * ($page - 1), $paginate);
$result = Paginator::make($slice, count($items), $paginate);

return View::make('yourView',compact('result'));

Solution 2

I faced this kind of issue already. I found a thread also not about pagination but about unions.

Please see this link : Sorting UNION queries with Laravel 4.1

@Mohamed Azher has shared a nice trick and it works on my issue.

$query = $query1->union($query2);
$querySql = $query->toSql();
$query = DB::table(DB::raw("($querySql order by foo desc) as a"))->mergeBindings($query);

This creates an sql like below:

select * from (
  (select a as foo from foo)
  union
  (select b as foo from bar)
) as a order by foo desc;

And you can already utilize Laravel's paginate same as usual like $query->paginate(5). (but you have to fork it a bit to fit to your problem)

Solution 3

Reiterating jdme's answer with a more elegant method from Illuminate\Database\Query\Builder.

$recipes = DB::table("recipes") ..
$items = DB::table("posts")->union($recipes) ..

$query = DB::query()
    ->fromSub($items, "some_query_name");

// Let's paginate!
$query->paginate(5);

I hope this helps!

Solution 4

The accepted answer works great for Query Builder.

But here's my approach for Laravel Eloquent Builder.

Assume that we're referring to same Model

$q1 = Model::createByMe();       // some condition
$q2 = Model::createByMyFriend(); // another condition

$q2->union($q1);
$querySql = $q2->toSql();

$query = Model::from(DB::raw("($querySql) as a"))->select('a.*')->addBinding($q2->getBindings());

$paginated_data = $query->paginate();

I'm using Laravel 5.6

Solution 5

order by

 $page = Input::get('page', 1);

 $paginate = 5;

 $recipes = DB::table("recipes")->select("id", "title", "user_id", "description", "created_at")
                ->where("user_id", "=", $id);
$items = DB::table("posts")->select("id", "title", "user_id", "content", "created_at")
            ->where("user_id", "=", $id)
            ->union($recipes)
            ->orderBy('created_at','desc')
            ->get();

$slice = array_slice($items, $paginate * ($page - 1), $paginate);
$result = Paginator::make($slice, count($items), $paginate);

return View::make('yourView',compact('result'))->with( 'result', $result );

View page :

   @foreach($result as $data)
  {{ $data->your_column_name;}}
 @endforeach 

  {{$result->links();}}   //for pagination

its help to more peoples.. because nobody cant understand show data in view page union with pagination and orderby .. thank u

View more solutions

Comments

[rmondesilva]

Encountered this problem. Try to use ->simplePaginate(n) instead.

[Lior]

Thanks! how would you add orderBy to the union query? i tried to add it after the ->union but the "order by" ends up within one of the parentheses (version 4.2.8).

[Alexandru Eftimie]

Loading all the rows in php and then slicing them is not very efficient, especially for large tables.

[mickmackusa]

Code-only answers do very little to educate SO readers. Your answer may or may not be a correct answer, but it is in the moderation queue after being marked as "low-quality". Please take a moment to improve your answer with an explanation.

[Qh0stM4N]

great answer, I am build spesific group by (exlude null and zero index) in merged 2 table union, this way working paginate and ordering.

[Martin Tonev]

The solution is right but for small amounts of data.

[Taras Chernata]

Wow Johnny! thank you so much, it works for me fine, after a day of struggling with similar issue)) Does it mean it will work fine if we have a lot of data, right??

[cawecoy]

I can't hold myself to say... Superb!

[Bogdan Burym]

Exactly the best answer, and the only right one.

[Ngoc Nam]

In order to get a large amout of data, it is a bad solution. Because ->get will get all data, then slice the array.

[sangam]

Useful when I don't want to miss my model as it has appended props.

[Zain Farooq]

It is not actually the solution but just virtual pagination to make the users happy.

[Abraham Putra Prakasa]

can't believe this is accepted answer lol