一、數據庫連接方式,

二、預處理後的返回

　　參考：http://www.php.net/manual/en/class.mysqli-stmt.php

　　註意。select查詢語句後要保存查詢結果。然後才有 num_rows;

<?php
/* Open a connection */
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");

/* check connection */
if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error
 
());
    exit();
}

$query = "SELECT Name, CountryCode FROM City ORDER BY Name LIMIT 20";
if ($stmt = $mysqli->prepare($query)) {

    /* execute query */
    $stmt->execute();

    /* store result */
    $stmt->store_result();

    printf("Number of rows: %d.\n", $stmt->num_rows);

    
 
/* close statement */
    $stmt->close();
}

/* close connection */
$mysqli->close();
?>

PHP預處理 CURD