何时在Laravel中使用雄辩的模型

Question

I am developing a set of backend APIs which will be used by an android/iphone app. There are instances where I have to use joins of more than 2 or 3 tables.

For example:

I have a products table that is associated with its likes, SKU's, comments, and category tables. If I am using eager loading to get all the values associated with the products table, it's going to execute the following queries:

select * from `products` where `products`.`products_id` = '1'
select * from `skus` where `skus`.`products_id` in ('1')
select * from `likes` where `likes`.`products_id` in ('1')
select * from `comments` where `comments`.`products_id` in ('1')

This has run 4 queries with all '*'. If I need to have specific columns to be selected, I will have to hardcode it in the model relationship function and it will not be dynamic. This will kill the performance and scalability of my application.

Where does the eloquent model come into play? Does it just give the advantage of faster development and an abstraction layer from the queries? Or are there any specific places where I can use eloquent model without compromising performance? What I understand is, if I have more tables, I better be using joins rather than eloquent?

Answer 1

Eloquent is an ORM. This ennables a user to use objective approach to set data and not to worry about how it is stored. No need to worry abbout sql injections and so on. But every ORM has a drawback. On (retrieving) complex data sets raw SQL is much more efficient in allot of cases. You can execute raw sql like this:

$products = \DB::table('products')
    ->where('products_id', 1)
    ->join('skus', 'skus.product_id', '=', 'products.product_id')
    ->join('likes', 'likes.product_id', '=', 'products.product_id')
    ->join('comments', 'comments.product_id', '=', 'products.product_id');