<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK IT ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006-2012 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------
namespace Think\Db\Driver;
use Think\Db\Driver;
/**
 * PDO数据库驱动 
 * @category   Extend
 * @package  Extend
 * @subpackage  Driver.Db
 * @author    liu21st <liu21st@gmail.com>
 */
class Mysql extends Driver{
    /**
     * 取得数据表的字段信息
     * @access public
     */
    public function getFields($tableName) {
        $this->initConnect(true);
        $sql   = 'SHOW COLUMNS FROM `'.$tableName.'`';
        $result = $this->query($sql);
        $info   =   [];
        if($result) {
            foreach ($result as $key => $val) {
                $info[$val['Field']] = array(
                    'name'    => $val['Field'],
                    'type'    => $val['Type'],
                    'notnull' => (bool) ($val['Null'] === ''), // not null is empty, null is yes
                    'default' => $val['Default'],
                    'primary' => (strtolower($val['Key']) == 'pri'),
                    'autoinc' => (strtolower($val['Extra']) == 'auto_increment'),
                );
            }
        }
        return $info;
    }

    /**
     * 取得数据库的表信息
     * @access public
     */
    public function getTables($dbName='') {
        $sql    = !empty($dbName)?'SHOW TABLES FROM '.$dbName:'SHOW TABLES ';
        $result = $this->query($sql);
        $info   =   [];
        foreach ($result as $key => $val) {
            $info[$key] = current($val);
        }
        return $info;
    }

    /**
     * 字段和表名处理
     * @access protected
     * @param string $key
     * @return string
     */
    protected function parseKey(&$key) {
        $key   =  trim($key);
        if(!preg_match('/[,\'\"\*\(\)`.\s]/',$key)) {
           $key = '`'.$key.'`';
        }
        return $key;            
    }

}