Use PDO singleton

src/DocumentList.php

@@ -18,11 +18,10 @@ class DocumentList
     /**
      * Constructor
      *
-     * @param PDO|null $pdo The database connection against which the query was opened
      * @param PDOStatement|null $result The result of the query
      * @param Mapper<TDoc> $mapper The mapper to deserialize JSON
      */
-    private function __construct(private ?PDO $pdo, private ?PDOStatement $result, private Mapper $mapper) { }
+    private function __construct(private ?PDOStatement &$result, private readonly Mapper $mapper) { }
 
     /**
      * Construct a new document list
@@ -35,8 +34,8 @@ class DocumentList
      */
     public static function create(string $query, array $parameters, Mapper $mapper): static
     {
-        $pdo = Configuration::dbConn();
-        return new static($pdo, Custom::runQuery($query, $parameters, $pdo), $mapper);
+        $stmt = &Custom::runQuery($query, $parameters);
+        return new static($stmt, $mapper);
     }
 
     /**
@@ -50,6 +49,5 @@ class DocumentList
             while ($row = $this->result->fetch(PDO::FETCH_ASSOC)) yield $this->mapper->map($row);
         }
         $this->result = null;
-        $this->pdo    = null;
     }
 }