cakephp/src/Database/Schema/Collection.php

<?php
/**
 * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
 * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 *
 * Licensed under The MIT License
 * For full copyright and license information, please see the LICENSE.txt
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 * @link          http://cakephp.org CakePHP(tm) Project
 * @since         3.0.0
 * @license       http://www.opensource.org/licenses/mit-license.php MIT License
 */
namespace Cake\Database\Schema;

use Cake\Database\Connection;
use Cake\Database\Exception;
use Cake\Database\Schema\Table;

/**
 * Represents a database schema collection
 *
 * Used to access information about the tables,
 * and other data in a database.
 */
class Collection {

/**
 * Connection object
 *
 * @var \Cake\Database\Connection
 */
	protected $_connection;

/**
 * Schema dialect instance.
 *
 * @var \Cake\Database\Schema\BaseSchema
 */
	protected $_dialect;

/**
 * Constructor.
 *
 * @param \Cake\Database\Connection $connection The connection instance.
 */
	public function __construct(Connection $connection) {
		$this->_connection = $connection;
		$this->_dialect = $connection->driver()->schemaDialect();
	}

/**
 * Get the list of tables available in the current connection.
 *
 * @return array The list of tables in the connected database/schema.
 */
	public function listTables() {
		list($sql, $params) = $this->_dialect->listTablesSql($this->_connection->config());
		$result = [];
		$statement = $this->_connection->execute($sql, $params);
		while ($row = $statement->fetch()) {
			$result[] = $row[0];
		}
		$statement->closeCursor();
		return $result;
	}

/**
 * Get the column metadata for a table.
 *
 * Caching will be applied if `cacheMetadata` key is present in the Connection
 * configuration options. Defaults to _cake_model_ when true.
 *
 * ### Options
 *
 * - `forceRefresh` - Set to true to force rebuilding the cached metadata.
 *   Defaults to false.
 *
 * @param string $name The name of the table to describe.
 * @param array $options The options to use, see above.
 * @return \Cake\Database\Schema\Table Object with column metadata.
 * @throws \Cake\Database\Exception when table cannot be described.
 */
	public function describe($name, array $options = []) {
		$config = $this->_connection->config();
		if (strpos($name, '.')) {
			list($config['schema'], $name) = explode('.', $name);
		}
		$table = new Table($name);

		$this->_reflect('Column', $name, $config, $table);
		if (count($table->columns()) === 0) {
			throw new Exception(sprintf('Cannot describe %s. It has 0 columns.', $name));
		}

		$this->_reflect('Index', $name, $config, $table);
		$this->_reflect('ForeignKey', $name, $config, $table);
		$this->_reflect('Options', $name, $config, $table);

		return $table;
	}

/**
 * Helper method for running each step of the reflection process.
 *
 * @param string $stage The stage name.
 * @param string $name The table name.
 * @param array $config The config data.
 * @param \Cake\Database\Schema\Table $table The table instance
 * @return void
 * @throws \Cake\Database\Exception on query failure.
 */
	protected function _reflect($stage, $name, $config, $table) {
		$describeMethod = "describe{$stage}Sql";
		$convertMethod = "convert{$stage}Description";

		list($sql, $params) = $this->_dialect->{$describeMethod}($name, $config);
		if (empty($sql)) {
			return;
		}
		try {
			$statement = $this->_connection->execute($sql, $params);
		} catch (\PDOException $e) {
			throw new Exception($e->getMessage(), 500, $e);
		}
		foreach ($statement->fetchAll('assoc') as $row) {
			$this->_dialect->{$convertMethod}($table, $row);
		}
		$statement->closeCursor();
	}

}