PHP之PDO的使用

pdo方式連接數據庫

try{
        $db = new PDO('mysql:host=127.0.0.1;dbname=test;port=3306;charset=utf8','root','123456');
}catch(PDOException $e){
        echo 'mysql error: '.$e->getMessage();
}

1.excu()方式增刪改，不推薦

$sql = "insert into test (username,password) values ('liming',123456)";
$res = $db->excu($sql);
echo $res //返回受影響的行數 1

2.PDOStatement類，增刪改(推薦用這種方式，速度快，可以防止sql注入)
方式1-推薦

$sql = "insert into test (username,password) values (:name,:password)";
$data = [':name'=>'liming',':password'=>123456];
$stmt = $db->prepare($sql);
$res  = $stmt->execute($data);
echo $res //返回受影響的行數 1

方式2,增刪改一樣

$name='maoxiaoming';//要插入的數據一定要先用變量定義，不然會報錯
$password= md5(123456);
$sql = $sql = "insert into test (username,password) values (:name,:password)";
$stmt = $db->prepare($sql);
$stmt->bindParam(':name',$name);
$stmt->bindParam(':password',$password);
$res = $stmt->execute();
echo $res //返回受影響的行數 1

3.PDOStatement類查詢所有數據

$sql  = "select * from user";
$stmt = $db->prepare($sql);
$stmt->execute();
$res = $stmt->fetchAll(PDO::FATCH_ASSOC);

//查詢一條

$sql = "select * from user where id=:id";
$data = [':id'=>3];
$stmt = $db->prepare($sql);
$stmt->execute($data);
echo '<pre>';
print_r($stmt->fetch(PDO::FETCH_ASSOC));