Partial

Raxos\Database\Query\Partial is a reusable sub query fragment that behaves as a query expression. It wraps a closure that builds a query; the closure receives the connection of the host query and is only invoked when the partial is compiled. A partial can therefore be constructed without a live connection and used anywhere a QueryExpressionInterface is accepted — inside Expr::exists(), a select, a where, and so on.

final readonly class Partial implements QueryExpressionInterface

Creating a partial

Use the partial() helper in the Raxos\Database\Query namespace instead of constructing the class directly:

use function Raxos\Database\Query\partial;

Function	Description
partial(Closure $query): Partial	Wraps a Closure(ConnectionInterface): QueryInterface as a reusable, lazily built sub query.

Behaviour

When the partial is compiled it invokes the closure with the host connection, then merges the resulting query as a parenthesized sub query — the same way Expr::subQuery() does, except the query is built lazily. Because building is deferred to compile time, the partial runs on the same connection as the host query and never depends on the global Db::query().

Example

<?php
declare(strict_types=1);

use Raxos\Contract\Database\ConnectionInterface;
use Raxos\Contract\Database\Query\QueryInterface;
use Raxos\Database\Db;
use Raxos\Database\Query\Expr;
use function Raxos\Database\Query\{column, partial};

// A reusable "has a paid order line" fragment.
$hasPaidOrderLine = partial(static fn(ConnectionInterface $connection): QueryInterface => $connection->query()
    ->select(1)
    ->from('order_line')
    ->where('product_id', column('id', 'product'))
    ->where('status', 'paid'));

$products = Db::query()
    ->select('*')
    ->from('product')
    ->where(Expr::exists($hasPaidOrderLine))
    ->array();

See Expr for the expression helpers a partial composes with.