用一条mysql语句插入多条数据

假设有一个数据表A:

id name title addtime

如果须要插入n条数据 :

$time= time();
$data = array(
  array(
   "name"=>"name1","title"=>"title1","addtime"=>$time;
  ),
  array(
   "name"=>"name2","title"=>"title2","addtime"=>$time;
  ),
  array(
   "name"=>"name3","title"=>"title3","addtime"=>$time;
  ),
  ...
  array(
   "name"=>"nameN","title"=>"titleN","addtime"=>$time;
  ),
  
);

之前我的想法会是，通过数据结构多条插入语句，重复调用。如:

$sql1 = "INSERT INTO `A`(`name`,`title`,`addtime`)VALUES ("name1","title1","".$time."")";
$sql2 = "INSERT INTO `A`(`name`,`title`,`addtime`)VALUES ("name2","title2","".$time."")";
......
$sqlN = "INSERT INTO `A`(`name`,`title`,`addtime`)VALUES ("nameN","titleN","".$time."")";

以后发明了sql的insert语句可以一次插入多条：

$sql = "INSERT INTO `A`(`name`,`title`,`addtime`)VALUES ("name1","title1","".$time.""),";
$sql .= "("name2","title2","".$time.""),";
$sql .= "("name3","title3","".$time.""),";
.....
$sql .= "("nameN","titleN","".$time."")";

通过","号将多个数据分隔开来，便可以够能过一条sql操作来解决多个数据的插入，之前实验时，在插入数据条数为30的情形下，一次插入与屡次插入一样数据的速度相比，一次插入快了近9倍。同时，由于插入操作只有一次，所以也相似事务操作，插入失败则全失败，插入胜利则全胜利，使数据的管理更加便利。所以，如果有多条数据须要插入同一个表的，尽可能用这类方法。

之前插入多条数据库记载时，常这么写：

$b = 14;

for($a=0;$a<100;$a++){

   $sql = " INSERT INTO `roles` (`uid`,`rid`) VALUES (".$a.",".$b.")";

   mysql_query($sql);

}

但这类写法效力低下，须要屡次履行sql语句。如果你用过phpmyadmin导入数据，其实你会发明，上面的语句其实可以这么写

   INSERT INTO `roles` (`uid`,`rid`) VALUES
       (534,14),(535,14),(536,14),(537,14),(539,14)

所以本来的代码可以这么改写

 $b = 14;

for($a=0;$a<100;$a++){

  if($a==0)

     $sql = "INSERT INTO `roles` (`uid`,`rid`) VALUES (".$a.",".$b.")";

  else

    $sql. = ",(".$a.",".$b.")";

}

mysql_query($sql);