/**
 * [copyDb description] 備份數(shù)據(jù)庫(kù)
 * @param [type] $dbname [description] 數(shù)據(jù)庫(kù)名
 * @param [type] $fileName [description] 存儲(chǔ)的文件名
 * @return [type]   [description]
 */
public function copyDb($dbname, $fileName){
	$myfile = fopen($fileName, "w") or die("Unable to open file!");//打開(kāi)存儲(chǔ)文件
	$this->link->query("use {$dbname}");//切換數(shù)據(jù)庫(kù)
	$this->changeDb($dbname);
	$tables = $this->link->query('show tables');//獲取當(dāng)期數(shù)據(jù)庫(kù)所有表名稱
	while($re = $tables->fetch(PDO::FETCH_ASSOC)){
		//var_dump($re);//查看數(shù)組構(gòu)成
		$tableName = $re['Tables_in_'.$dbname];//構(gòu)成特定的下標(biāo)
		$sql = "show create table {$tableName};";
		$tableSql = $this->link->query($sql);

		fwrite($myfile, "DROP TABLE IF EXISTS `{$tableName}`;\r\n");//加入默認(rèn)刪除表的遇見(jiàn)
		//下面?zhèn)浞荼斫Y(jié)構(gòu)，這個(gè)循環(huán)之執(zhí)行一次
		while($re = $tableSql->fetch(PDO::FETCH_ASSOC)){
			// echo "<pre>";
			// var_dump($re);
			// echo "</pre>";
			echo "正在備份表{$re['Table']}結(jié)構(gòu)<br/>";
			fwrite($myfile, $re['Create Table'].";\r\n\r\n");
			echo "正在備份表{$re['Table']}結(jié)構(gòu)完成<br/>";
		}
		//下面?zhèn)浞荼頂?shù)據(jù)
		echo "正在備份表{$tableName}數(shù)據(jù)<br/>";
		$sql = "select * from {$tableName};";
		$valueSql = $this->link->query($sql);
		while($re = $valueSql->fetch(PDO::FETCH_ASSOC)){
			$keyArr = array_keys($re);//獲得對(duì)應(yīng)的鍵值
			$valueArr = array_values($re);//獲得對(duì)應(yīng)的值
	
			$keyStr = '';
			foreach ($keyArr as $key => $value) {
				$keyStr .= "`".$value."`,";
			}
			$keyStr = substr($keyStr,0,strlen($keyStr)-1); //取出最后一個(gè)逗號(hào)


			$valueStr = '';
			// var_dump($valueArr);
			foreach ($valueArr as $key => $value) {
				$valueStr .= "'".$value."',";
			}
			//以上的處理只是對(duì)應(yīng)sql的寫(xiě)法

			$valueStr = substr($valueStr,0,strlen($valueStr)-1); //取出最后一個(gè)逗號(hào)
			$sql = "insert into `{$tableName}`({$keyStr}) values({$valueStr})";
			fwrite($myfile, $sql.";\r\n\r\n");
			
		}
		echo "正在備份表{$tableName}數(shù)據(jù)完成<br/>";
		echo "<br/><hr/>";
	}
	fclose($myfile);
}