$db = MysqL_connect("host:port","username","paswword");

MysqL_select_db("my_db",$db);

# say we want to select everything from the table Persons
$result = MysqL_query("SELECT * FROM Persons");

while ($row = MysqL_fetch_array($result))
{
   # do your magic
   # columns are accessed in a zero based array
   # such as $row[0],$row[1],etc. 
   # look at MysqL_fetch_assoc to see how to access
   # using the column names
}

MysqL_close($db);

有一个看起来像旧的但仍然有效的W3c tutorial here和那里的MySQL PHP API reference.要了解API差异,请阅读Overview of the MySQL PHP drivers.

正如其他答案所述,您希望PHP输出类似JSON或XML的内容,以便与您的应用程序和XCode进行通信.