Question:
In Laravel , we have a method that we can list fields from a table in key-value style.
I can do this in two ways
So:
Usuario::lists('nome', 'id');
And so:
Usuario::all()->lists('nome', 'id');
The result of this would be:
[1 => 'Wallace', 2 => 'Guilherme', 3 => 'Bigown', 4 => 'Miguel']
But since there are two ways to do this, what's the difference between the two?
Answer:
Well, the difference is this: When you invoke lists you make only specific fields specified in laravel's Orm query and put them in an array .
Example:
Usuario::lists('nome', 'id');
It is the same as :
SELECT nome, id FROM usuarios
The case of the all method followed by lists is something else. When we call Usuario::all() we bring all existing results in the usuarios table and with all fields selected.
SELECT * FROM usuários
The all method will return an object called Illuminate\Database\Eloquent\Collection . This object, in turn, has the all method. But internally, it uses the function called array_pluck to capture only the two items passed, such as key and value.
performance
The performance difference is noticeable between the two explanations. lists I gained both in the execution of the query and in the amount of data brought to PHP.
If you're just going to bring up a list containing the key-value pair from the bank, you should use lists .
However, there are cases where, in addition to bringing the complete user data, for reasons of need of a certain type, you would want to transform an Eloquent\Collection object into an array .
In this case, we are talking about an object-oriented concept called Reuse.
An example of this is needing to bring all user data to make a listing in a table, but at the same time needing a listing of these users in a select (then it will be necessary to use lists this collection, so as not to make another SELECT in the database).
I'll give you an example:
$usuario = Usuario::all();
// Preciso da lista de nomes e ids para passar para um "select" no html
$usuarios_lista = $usuarios->lists('nome', 'id');