Mysqli:预编译 mysqli_stmt

       当数据库操作语句很多时，传统的方法：每次传一条操作语句，数据库都需要先编译，然后关闭；而数据库编译语句的时间仅次于连接时间，所以造成时间过长，效率不高；所以PHP作者想到用预编译的方法，只需预编译一次，后面传的都是数据，大大节省了数据库编译时间，效率迅速提高！！！

$mysqli=new mysqli("localhost","root","123456","test002");
if($mysqli->connect_error){
    die ("LINK FAILED".$mysqli->connect_error);
}
$query="insert into user1 (name,password,email,age) values (?,?,?,?)";
$stmt=$mysqli->prepare($query);
$stmt->bind_param('sssi',$name,$password,$email,$age);
$name="Polly";
$password="74E738";
$email="[email protected]";
$age=34;
$b=$stmt->execute();
if(!$b){
    echo "FAILED".$stmt->error;
}else{
    echo "SUCCESS";
}
$name="Lily";
$password="74E738";
$email="[email protected]";
$age=24;
$stmt->execute();
$name="Luna";
$password="74E738";
$email="[email protected]";
$age=29;
$stmt->execute();

echo "

END";
$mysqli->close();

$mysqli=new mysqli("localhost","root","123456","test002");
if($mysqli->connect_error){
    die ("LINK FAILED".$mysqli->connect_error);
}
$mysqli->query("set names utf8");
$query="select id,name,email,age from user1 where id>?";
$stmt=$mysqli->prepare($query);
$stmt->bind_param('i',$id);
$id=8;
$stmt->bind_result($id,$name,$email,$age);
$stmt->execute();
while($stmt->fetch()){
    echo "
--$id--$name--$email--$age";
}

echo "
***************************************************************************";
$id=38;
$stmt->execute();
while($stmt->fetch()){
    echo "
--$id--$name--$email--$age";
}
//释放内存结果集；
$stmt->free_result();
//关闭预编译；
$stmt->close();
$mysqli->close();