A PHP library for Interrogatory Messages., (*1)
Interrogatory Messages are passed
to the QueryBus service which returns the result of the first QueryMatcher
that supports it., (*2)
Installation
QueryBus can be installed using Composer:, (*3)
composer require "gnugat/query-bus:~2.0"
Simple conversion
Let's take the following table:, (*4)
CREATE TABLE article (
id int,
title VARCHAR(255),
content TEXT
);
If we want to execute the following query:, (*5)
SELECT id, title, content FROM article WHERE id = 42;
Then we have first to create a Query, which is a simple
DTO:, (*6)
<?php
require __DIR__.'/vendor/autoload.php';
use Gnugat\QueryBus\QueryBus;
class GetArticle
{
public $id;
public function __construct($id)
{
if (null === $id) {
throw new \InvalidArgumentException('Required parameter ID is missing');
}
$this->id = (int) $id;
}
}
Note: Queries can contain simple validation,
for example to check for null values., (*7)
Then we have to create a QueryMatcher:, (*8)
// ...
use Gnugat\QueryBus\QueryMatcher;
class GetArticleMatcher implements QueryMatcher
{
private $connection;
public function __construct($connection)
{
$this->connection = $connection;
pg_prepare($this->connection, 'get_article', 'SELECT id, title, content FROM articles WHERE id = $1');
}
public function supports($query)
{
return $query instanceof GetArticle;
}
public function match($query)
{
$result = pg_execute($this->connection, 'get_article', array($query->id));
return pg_fetch_array($result, NULL, PGSQL_ASSOC);
}
}
Next we need to register it in QueryBus:, (*9)
// ...
use Gnugat\QueryBus\QueryBus;
$connection = pg_pconnect('dbname=blog');
$queryBus = new QueryBus();
$queryBus->add(new GetArticleMatcher($connection));
Finally we can actually execute the query:, (*10)
// ...
$articles = $queryBus->match(new GetArticle(42));
Further documentation
You can see the current and past versions using one of the following:, (*11)
You can find more documentation at the following links:, (*12)
Wallogit.com
