<?php 

/* Connect to a MySQL server */ 
$link = mysqli_connect( 
           'localhost',  /* The host to connect to */ 
           'user',       /* The user to connect as */ 
           'password',   /* The password to use */ 
           'world');     /* The default table to query */ 

if (!$link) { 
  printf("Can't connect to MySQL Server. Errorcode: %s\n", mysqli_connect_error()); 
  exit; 
} 

/* Send a query to the server */ 
if ($result = mysqli_query($link, 'SELECT Name, Population FROM City ORDER BY Population DESC LIMIT 5')) { 

   print("Very large cities are:\n"); 

   /* Fetch the results of the query */ 
   while( $row = mysqli_fetch_assoc($result) ){ 
       printf("%s (%s)\n", $row['Name'], $row['Population']); 
   } 

   /* Destroy the result set and free the memory used for it */ 
   mysqli_free_result($result); 
} 

/* Close the connection */ 
mysqli_close($link); 
?> 

输出结果：

Very large cities are:

Mumbai (Bombay) (10500000)
Seoul (9981619)
São Paulo (9968485)
Shanghai (9696300)
Jakarta (9604900)

2.使用内置OO接口方式调用：

<?php 

/* Connect to a MySQL server */ 
$mysqli = new mysqli('localhost', 'user', 'password', 'world'); 

if (mysqli_connect_errno()) { 
  printf("Can't connect to MySQL Server. Errorcode: %s\n", mysqli_connect_error()); 
  exit; 
} 

/* Send a query to the server */ 
if ($result = $mysqli->query('SELECT Name, Population FROM City ORDER BY Population DESC LIMIT 5')) { 

   print("Very large cities are:\n"); 

   /* Fetch the results of the query */ 
   while( $row = $result->fetch_assoc() ){ 
       printf("%s (%s)\n", $row['Name'], $row['Population']); 
   } 

   /* Destroy the result set and free the memory used for it */ 
   $result->close(); 
} 

/* Close the connection */ 
$mysqli->close(); 
?> phpma开源

支持的新特性还有：Bound Parameters，Bound Results等。。。
有兴趣的可以直接去参看原英文：
http://www.zend.com/php5/articles/php5-mysqli.php#fn3

注：感觉这个不是对所有人都有用。不过。。。相信可以帮助大家多了解些“变化”，能更好的把握“趋势” 8-)