PHP中使用匿名函数操作数据库的例子

代码如下:
Base dao class illustrating the usefulness of closures.
* Handles opening and closing of connections.
* Adds slashes sql
* Type checking of sql parameters and casts as appropriate
* Provides hook for processing of result set and emitting one or more objects.
* Provides hook for accessing underlying link and result objects.

<?php

define("userName","root");
define("password","root");
define("dbName","ahcdb");
define("hostName","localhost");

class BaseDao {

    function getConnection()    {
        $link = mysql_connect(hostName, userName, password);
        if (!$link)
            die("Could not connect: " . mysql_error());
        if (!mysql_select_db(dbName))
            die("Could not select database: " . mysql_error());
        return $link;
    }
   
    function setParams(& $sql, $params)    {
        if($params != null)
            $sql = vsprintf($sql, array_map(function($n) {
                if(is_int($n))
                    return (int)$n;
                if(is_float($n))
                    return (float)$n;
                if(is_string($n))
                    return "'".mysql_real_escape_string($n)."'";
                return mysql_real_escape_string($n);
            }, $params));
    }

    function executeQuery($sql, $params, $callback = null)    {
        $link  = $this->getConnection();
        $this->setParams($sql, $params);
        $return = null;
        if(($result = mysql_query($sql, $link)) != null)
            if($callback != null)
                $return = $callback($result, $link);