Putting eloquent results in another table to doing where queries in Laravel 5.4 - laravel

Question

For some special reasons I used append attributes in my model and now when I want to do where queries on custom attributes, for example "category", I face an error with this meaning that eloquent could not found column with "category" name!
To solve this problem I guess if I put my query's result into a temp table, I could do what I want!
Have someone any Idea about that? If it's useful to me, How can I transfer my results to the temp table?

Answer 1

You won't be able to limit the database query using a Model accessor's dynamic field, since that field obviously doesn't exist in the database.
However, the Collection object has fairly robust filtering capabilities, so you could filter the Collection results using the dynamic fields after the database has been queried. This is not as performant as filtering out the results before they are retrieved from the database, but you may be a situation where the performance isn't that critical or the code cleanliness/maintenance cost outweighs the performance cost.
As an example, given the following Model:
class Book extends Model
{
public function getCategoryAttribute()
{
if ($this->targetAge < 13) {
return 'child';
}
if ($this->targetAge < 18) {
return 'teen';
}
return 'adult';
}
}
The following query will not work because the category field doesn't actually exist in the table:
$childrenBooks = Book::where('category', 'child')->get(); // error: no category field
However, the following will work, because you're calling where() on the Collection of Models returned from the database, and the Models do have access to the dynamic field:
$childrenBooks = Book::get()->where('category', 'child');
The problem in this case is that, while it does work, it will get all the books from the database and create a Model instance for each one, and then you filter through that full Collection. The benefit, however, is that you don't have to duplicate the logic in your accessor method. This is where you need to weigh the pros and cons and determine if this is acceptable in your situation.
An intermediate option would be to create a Model scope method, so that your accessor logic is only duplicated in one place (if it can be duplicated for a query):
class Book extends Model
{
public function getCategoryAttribute()
{
if ($this->targetAge < 13) {
return 'child';
}
if ($this->targetAge < 18) {
return 'teen';
}
return 'adult';
}
public function scopeCategory($query, $category)
{
if ($category == 'child') {
return $query->where('target_age', '<', 13);
}
if ($category == 'teen') {
return $query->where(function ($query) {
return $query
->where('target_age', '>=', 13)
->where('target_age', '<', 18);
});
}
return $query->where('target_age', '>=', 18);
}
}
Then you can use this query scope like so:
$childrenBooks = Book::category('child')->get();
The benefit here is that the logic applies to the actual query, so the records are limited before they are returned from database. The main problem is that now your "category" logic is duplicated, once in an accessor and once in a scope. Additionally, this only works if you can turn your accessor logic into something that can be handled by a database query.

Answer 2

You can create temporary tables using raw statements. This post goes fairly in depth over it:
https://laracasts.com/discuss/channels/laravel/how-to-implement-temporary-table