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Osm Admin: Better Query Model

2021 November Osm Admin

2 years ago ∙ 1 minute read

I decided to support selecting, filtering and ordering by properties of a related object using dot syntax: product.price, parent.level. This syntax will automatically join the table that stored related objects.

I realized that implementing joins requires a better query model than my current naive wrapper around Laravel query. This article describes the new query model.

Query Methods

The query() function returns an instance of a class that extends the Query class:

/* @var TableQuery $query */
$query = query(Scope::class);

The query object will have methods for applying filters, selecting properties, and ordering by them:

$scope = query(Scope::class)
    ->whereEquals('parent_id', 1)
    ->or(fn(Filter\Logical\Or_ $q) => $q
        ->whereGreaterThan('id, 5')
    ->orderBy('title', Query::ASCENDING)
    ->first(['id', 'title', 'parent.title']);

All these methods will add filters, order, and selection to internal arrays: filters, orders and columns, respectively.

And when call the first(), get() or other method that actually hits the database, the internal arrays will be converted to the Laravel query, which will execute actual SQL.

New Query Model

So let's see how the query will store its configuration:

Query Model

Query methods add Column, Order and Filter objects to the respective arrays.

Filters can be of different types: equality filter, nullability filter, regex matching filter, and more. Logical filters, such as logical OR, may have child filters - operands.

What's Next

I've started a refactoring based on this model, and implementing the dot syntax, and soon it will be clear how it goes, so stay tuned!