[MySqli扩展]②--mysqli使用解析

Paste_Image.png

Paste_Image.png

连接打开数据库

$mysqli = new mysqli

$mysqli = new mysqli('localhost', 'root', '');
//print_r($mysqli);
$mysqli->select_db('test');

$mysqli = new mysqli();
$mysqli->connect('127.0.0.1', 'root', '',

$mysqli = new mysqli('localhost','root','','test');

得到错误信息

$mysqli->connect_error

$mysqli = @new mysqli('localhost', 'root', '123', 'test');
if ($mysqli->connect_errno) {
    die('Connect Error:' . $mysqli->connect_error);
}

Paste_Image.png

获取客户端和用户端信息

$mysqli->client_info

$mysqli->server_info

client_info . '
';
echo $mysqli->get_client_info() . '
';

echo '客户端的版本: ' . $mysqli->client_version . "
";

echo "服务器端信息：" . $mysqli->server_info . "
";

echo "服务器版本：" . $mysqli->server_version . "
";

?>

Paste_Image.png

SELECT/DESC/DESCRIBE/SHOW/EXPLAIN执行成功返回mysqli_result对象，执行失败返回false 对于其它SQL语句的执行，执行成功返回true,否则返回false

connect_errno) {
    die('Connect Error:' . $mysqli->connect_error);
}

$mysqli->set_charset('utf8');

$sql = <<query($sql);
var_dump($res);//boolean true

//关闭连接
$mysqli->close();

?>

Paste_Image.png