Please have a look at the following code:
$msgs = Message::where(function($query) use ($start,$end){
$query->whereBetween('created_at', array($start, $end));
})->orderBy('created_at', 'DESC');
$first = $msgs->first()->created_at;
$ids = $msgs->lists('id');
What I'm trying to do is to get the latest date of the query result set and get all the ids from the result at the same time. But the code doesn't work because the $msgs was changed by the $msgs->first() function. I'm wondering if there is a way to let me get the first element of the query result without affecting the whole result set? Thanks
$first = $msgs->first(); // this does ->take(1) under the hood
Now your builder has limit = 1
clause.
So basically you need this:
// also you can use pluck:
$first = $msgs->pluck('created_at'); // returns first row`s single field
//then:
$ids = $msgs->take(9999)->lists('id'); // some high value depending on your data
Your solution is not the best, as it loads all the rows and creates objects of them, while all you need is list of ids.
You can also use first()
method of the Collection to fetch its first item, instead of that foreach loop:
$messages = $msgs->get();
$first = $msgs->first()->created_at;