Feature request: TotalCache (similar to CountCache)

[cviebrock]

In the same way we can add count caching to a model, it would be nice to have a behaviour that cached the sum of some value.

As an example, a User has many Orders. Right now, we could add a order_count field to the User model and use the existing behaviour to update that. I'm suggesting something that allows one to add a an order_total field as well, that is a cached copy of the sum of some field on the Orders table for that User. e.g.

UPDATE users SET order_total = (
  SELECT SUM(orders.amount) AS total FROM orders WHERE orders.user_id = users.id
) WHERE users.id = ?

Not sure how the configuration would look, but maybe something like this on the Order class:

public function totalCaches()
{
    // short syntax
    return [
        // class => fieldToSum
        User::class => 'amount'
    ];

    // full syntax
    return [
        // fieldName => [ class, foreignKey, key, fieldToSum ]
        'order_total' => [User::class, 'user_id', id', 'amount'],
    ];
}

[kirkbushell]

Yeah I've thought about that also, and it'll be a good feature (same with average). It fits well with the behaviours idea and system of Eloquence, so I'm happy to include something like this.

[cviebrock]

If you have a chance, can you take a look at the PR #35 I submitted? It's not passing the tests ... but I think that's because I have something set up incorrectly in the tests, not in the actual implementation.

Thanks!

[kirkbushell]

Will do @cviebrock - just been away on holidays (and currently sick).

[cviebrock]

Get well soon!

[kirkbushell]

I'll be renaming the SumCache to TotalCache - I think it's a better name :) Thanks for this.

[cviebrock]

Your package, so your call. :) I was trying to keep parity with the underlying SQL commands normally associated with the actions:

• COUNT() --> CountCache
• SUM() --> SumCache
• AVG() --> AvgCache (..eventually)

And thanks!

[kirkbushell]

hehe, I ended up reverting it back to sum anyway - Summable works nicely as a trait ^_^

[cviebrock]

Rolls off the tongue better than Totalable. ;)