PgSqlDriver: uses cache for getColumnTypes() to avoid excessive number of queries [Closes #212]

Author: dg

src/Database/Drivers/PgSqlDriver.php

@@ -218,7 +218,12 @@ public function getForeignKeys(string $table): array
 
 	public function getColumnTypes(\PDOStatement $statement): array
 	{
-		return Nette\Database\Helpers::detectTypes($statement);
+		static $cache;
+		$item = &$cache[$statement->queryString];
+		if ($item === null) {
+			$item = Nette\Database\Helpers::detectTypes($statement);
+		}
+		return $item;
 	}