<?php

namespace common\replaces;

use yii\db\Transaction;

/**
 * 兼容mycat的操作
 * @Author bing
 * @DateTime 2021-10-14 10:42:07
 * @copyright: Copyright (c) 2020 广东七件事集团
 */
class Connection extends \yii\db\Connection
{
    /**
     * @var array An array of [[setQueryBuilder()]] calls, holding the passed arguments.
     * Is used to restore a QueryBuilder configuration after the connection close/open cycle.
     *
     * @see restoreQueryBuilderConfiguration()
     */
    private $_queryBuilderConfigurations = [];
    /**
     * @var Transaction the currently active transaction
     */
    private $_transaction;
    /**
     * @var Schema the database schema
     */
    private $_schema;
    /**
     * @var string driver name
     */
    private $_driverName;
    /**
     * @var Connection|false the currently active master connection
     */
    private $_master = false;
    /**
     * @var Connection|false the currently active slave connection
     */
    private $_slave = false;
    /**
     * @var array query cache parameters for the [[cache()]] calls
     */
    private $_queryCacheInfo = [];
    /**
     * @var string[] quoted table name cache for [[quoteTableName()]] calls
     */
    private $_quotedTableNames;
    /**
     * @var string[] quoted column name cache for [[quoteColumnName()]] calls
     */
    private $_quotedColumnNames;


    /**
     * Starts a transaction.
     * @param string|null $isolationLevel The isolation level to use for this transaction.
     * See [[Transaction::begin()]] for details.
     * @return Transaction the transaction initiated
     */
    public function beginTransaction($isolationLevel = null)
    {
        $this->open();

        if (($transaction = $this->getTransaction()) === null) {
            $transaction = $this->_transaction = new Transaction(['db' => $this]);
            $transaction->begin($isolationLevel);
        }

        return $transaction;
    }

    public function getTransaction()
    {
        return $this->_transaction && $this->_transaction->getIsActive() ? $this->_transaction : null;
    }
}