使用预处理语句实现数据查询的方法

$m=new mysqli('localhost','root','','db');

$m->set_charset('utf8');

$stmt=$m->prepare('select count(*) from stu');

$stmt->execute();

$stmt->bind_result($c);

$stmt->fetch();

echo $c;

$stmt->free_result();

$stmt->close();

$m->close();

$m=new mysqli('localhost','root','','db');

$m->set_charset('utf8');

$stmt=$m->prepare('select * from stu where 1=1');

$stmt->execute();

$stmt->bind_result($id,$name,$sgender,$sscore);

while($stmt->fetch()){

echo "$id,$name,$sgender,$sscore".'<br>';

}

$stmt->free_result();

$stmt->close();

$m->close();

$m=new mysqli('localhost','root','','db');

$m->set_charset('utf8');

$stmt=$m->prepare('select * from stu where 1=1');

$stmt->execute();

$result=$stmt->get_result();

$rows=$result->fetch_all(2);

foreach($rows as $v){

print_r($v).'<br>';

}

$stmt->free_result();

$stmt->close();

$m->close();

$m=new mysqli('localhost','root','','db');

$m->set_charset('utf8');

$stmt=$m->prepare('select * from stu where sid=?');

$n=10;

$stmt->bind_param('i',$n);

$stmt->execute();

$stmt->bind_result($id,$name,$sgender,$sscore);

$stmt->fetch();

echo $id,$name,$sgender,$sscore;

$stmt->free_result();

$stmt->close();

$m->close();