一般情况下,查询用到的次数远比增删查要多。
那么PDO如何查询呢?直接上代码!!!
$atime=5;
$pdo=new PDO('mysql:host=127.0.0.1;dbname=test1','root','root');
$stmt=$pdo->prepare('select * from test where atime>:atime');
$stmt->bindParam(':atime',$atime);
$stmt->execute();
$stmt=$pdo->prepare('select * from test where atime>:atime');
$stmt->bindParam(':atime',$atime);
$stmt->execute();
//查询单条数据
$a=$stmt->fetch(PDO::FETCH_ASSOC);//关联数组print_r($a);
$a=$stmt->fetch(PDO::FETCH_LAZY);//只能用于单条查询
//PDORow Object
//(
// [queryString] => select * from test where atime>:atime
// [id] => 7
// [aname] => aa
// [atime] => 23
//)
//查询多条数据
$a=$stmt->fetchAll(PDO::FETCH_ASSOC);//关联数组
//索引键
$a=$stmt->fetchAll(PDO::FETCH_NUM);//索引键
//既有索引键也有关联键
$a=$stmt->fetchAll(PDO::FETCH_BOTH);//既有索引键也有关联键
Array
//(
// [0] => Array
// (
// [id] => 7
// [0] => 7
// [aname] => aa
//[1] => aa
//[atime] => 23
// [2] => 23
// )
//
// [1] => Array
//(
// [id] => 8
// [0] => 8
// [aname] => aa
//[1] => aa
//[atime] => 23
// [2] => 23
// )
嗯,就是如此简单~