Using Laravel 5.3, I have a model with the following function
public function myData() {
return $this->hasMany(MyData::class);
}
and in my collection I have the following
$my_data = MyModel->myData()->get();
All good so far. If I return $my_data I get an eloquent collection with three items.
What I need now though is to create a duplicate of that collection but containing only three of the fields.
I have tried several different things, each of which return an error. The following is the closest I have got, but this returns an empty array - I assume because the fields are located one level deeper than the collection object.
$new_collection = $my_data->only(['field_1', 'field_2', 'field_3']);
What would be the correct way to create a new collection containing all three items, each with only the three selected fields?
Thanks for your help
You could use map:
$slimmed_down = $collection->map(function ($item, $key) {
return [
'field_1' => $item->field_1,
'field_2' => $item->field_2,
'field_3' => $item->field_3
];
});
This will return a new Collection with just the values you want. As far as I know there isn't any other method that does what you want, so iterating over every item and selecting the fields this way is one of the few solutions.
The advantage of using map instead of a standard foreach loop is that when you use map it returns a new instance of Collection.
Edit:
After some thoughts and research about this, the problem you'll have created is that the all the values in the Collection aren't instances of anything anymore. If you don't mind this effect, an even prettier and faster way would be to do this:
$slimmed_down = $collection->toArray()->only(['field_1', 'field_2', 'field_3']);
This basically has the same result.
Using Laravel 9, I just had the same issue :
$my_data->only(['field_1', 'field_2', 'field_3']);
returning an empty array.
I solved it with :
$my_data->map->only(['field_1', 'field_2', 'field_3']);
Related
I have a challenge that if I want to sort the records when getting using Laravel's ORM based on a list of IDs, how should I do it?!!!!!!!
I mean :
Suppose we have a table called users, which contains 100 records and each record has a unique ID.
We also have an array of IDs.
$ids = [4,1,2,3]
Now I want to get the list of users, but only the users who are first in the ids array and secondly according to the same order as they are listed in this array.
User::whereIn('id' , $Ids)->sortBy('id',$ids)->get();
Can you think of a solution to do this?
User::whereIn('id' , $Ids)->sortBy('id',$ids)->get();
The collections sortBy() function can take a custom call back this way:
$users = User::whereIn('id', $Ids)->get()
->sortBy(function($user, $key) use($ids) {
return array_search($user->id, $ids);
});
This will sort your collection according to the given array.
You can also reference the docs for more information.
Note that the sortBy() function must act upon a collection, which means that the get() function must come before it.
quite a noob in Laravel and Livewire, I guess if there is a better way to accomplish what I have here:
I have some checkboxes in a Livewire view that allow the user to dynamically choose how to filter the data being shown in a HTML table.
On the controller I have an eloquent query that retrieves a subset of the records in the db whenever a checkbox changes state.
Like this (I tried to simplify the structure):
$filtered_items = Item::select('item_color', 'item_quantity', 'item_value')
->whereIn('item_color', [ /* array controlled by checkboxes values in view */ ])
->get();
I need to also show the sums of some columns for that specific filter setup.
As I don't want to make new queries, I try to work on the already available collection with a ->sum() for each column I want to sum:
$sums['item_quantity'] = $filtered_items->sum('item_quantity');
$sums['item_value'] = $filtered_items->sum('item_value');
It works as intended, as I have an array with the sums, but I was wondering if there is a better way to do this, or even write a function to get more columns sum at once, maybe passing an array.
Thanks for any idea or link!
Here is an example of a single query for all sums (two in this example)
$filtered_items = \DB::table('items')
->selectRaw('SUM(item_quantity) as sum_quantity, SUM(item_value) as sum_value')
->whereIn('item_color', [ /* array controlled by checkboxes values in view */ ])
->first();
The advantage is that it will return one entry/row instead of a collection of all the items which is way faster.
I have some properties and i want to get the object for each property, currently, I am using the eloquent in the foreach loop like this as shown in the image that will describe the best..
but it is really not a good approach because if I have 100 published property I will making 100 calls to the DB... and that is not correct?
I need a suggestion and a proper solution to this query?
Thanks in advance
Before foreach you can get all the RentalProperty items from db like this:
$allRentalProperties = RentalProperty::all();
and in foreach loop you can get those items without connecting database like this:
$propertyObj = $allRenatalProperties -> where('id', $property['id']) -> first();
Also, you can use array shorthand.
$newArray = [];
it's much simple and readable.
You can do array pluck before loop:
$propertyIds = Arr::pluck($published_properties, 'id');
Then you can make a whereIn query to get only those data which are in $published_properties object
$propertyObj = RentalProperty::whereIn('id', $propertyIds);
Then you can access that object with id if you change array key with record id.
I have some instances where a eloquent is resulting an single array not a collection. Although dd shows it as a collection with a single entry.
For example I have a query in a controller:
$pg = Page::with('getPanels')->where('slug',$slug)->get();
This will return a single result and works fine, so I pass this to a blade template. My complete function is
$pg = Page::with('getPanels')->where('slug',$slug)->get();
return view('front.page',['pg' => $pg]);
As soon as he template is brought in it will fall over at
if (!is_null($pg->headImage))
{$img = asset('images/pages')."/".$pg->headImage;}
and I will get
Property [headImage] does not exist on this collection instance.
If I change the line to
if (!is_null($pg[0]['headImage']))
it will continue OK. This is of course a pain as I would much rather use $pg->headImage.
Can someone enlighten me please?
I have sorted this and I hope it will help other people.
If I use
$pg = Page::with('getPanels')->where('slug',$slug)->first();
it will be just one result (naturally) and therefore
$pg->headImage
will fail as it wants
$pg[0]['headImage']
but if I change the eloquent instead of get(0 to first() (still just one result)
$pg = Page::with('getPanels')->where('slug',$slug)->first();
I can use $pg->headImage or what field I want.
I am new to laravel and confused about some query methods.
find($id) is useful and returns a nice array, but sometimes I need to select by other fields rather than id.
The Laravel document said I could use where('field', '=', 'value') and return a bunch of data, which is fine.
What I can't understand is why I need to add ->first() every time, even if I am pretty sure there is only one single row matches the query.
It goes like this:
$query->where(..)->orderBy(..)->limit(..) etc.
// you can chain the methods as you like, and finally you need one of:
->get($columns); // returns Eloquent Collection of Models or array of stdObjects
->first($columns); // returns single row (Eloquent Model or stdClass)
->find($id); // returns single row (Eloquent Model or stdClass)
->find($ids); // returns Eloquent Collection
// those are examples, there are many more like firstOrFail, findMany etc, check the api
$columns is an array of fields to retrieve, default array('*')
$id is a single primary key value
$ids is an array of PKs, this works in find method only for Eloquent Builder
// or aggregate functions:
->count()
->avg()
->aggregate()
// just examples here too
So the method depends on what you want to retrieve (array/collection or single object)
Also the return objects depend on the builder you are using (Eloquent Builder or Query Builder):
User::get(); // Eloquent Colleciton
DB::table('users')->get(); // array of stdObjects
even if I am pretty sure there is only one single row matches the query.
Well Laravel cant read your mind - so you need to tell it what you want to do.
You can do either
User::where('field', '=', 'value')->get()
Which will return all objects that match that search. Sometimes it might be one, but sometimes it might be 2 or 3...
If you are sure there is only one (or you only want the first) you can do
User::where('field', '=', 'value')->first()
get() returns an array of objects (multiple rows)
while
first() returns a single object (a row)
You can of course use get() when you know it will return only one row, but you need to keep that in mind when addressing the result:
using get()
$rez = \DB::table('table')->where('sec_id','=','5')->get();
//will return one row in an array with one item, but will be addressed as:
$myfieldvalue = $rez[0]->fieldname;
using first()
$rez = \DB::table('table')->where('sec_id','=','5')->first();
// will also return one row but without the array, so
$myfieldvalue = $rez->fieldname;
So it depends on how you want to access the result of the query: as an object or as an array, and also depends on what "you know" the query will return.
first() is the equivalent of LIMIT 1 at the end of your SELECT statement. Even if your query would return multiple rows, if you use first() it will only return the first row