php - 如何从不同文件和数组变量中的 mysql_fetch_assoc() 访问连续行？

Question

我正在尝试从城市的地点/地点表中实现一个简单的“列出”功能。

为此，我创建了一个 Place 类并从“get”函数返回一个 mysql_fetch_assoc() 数组。该代码位于名为“placeops.php”的 PHP 文件中，仅包含 OO 逻辑。

现在转到另一个名为“displayplaces.php”的文件，我在这里调用相同的“get”函数将 mysql_fetch_assoc() 数组获取到另一个变量中。然后我使用 next() 和 current() 函数来检索记录。

这行不通。如果我使用 current() 获取特定的列/属性值，它会显示“current() 需要数组，字符串已传递”错误。通过不使用 current()，我只能访问第一个元素，如预期的那样。我明白为什么会出现这个错误。但有什么解决办法吗？我必须使用面向对象的方法。代码如下:

//This is the class and the function I use to return the mysql array. The file name is
//   placeops.php

<?php


//include '../../../myclass.php';
@mysql_connect("localhost","root","") or die(mysql_error());
mysql_select_db("wom") or die(mysql_error());

global $plcname, $plcaddr, $plccity, $plcstate, $plcpic, $plcrating, $plclat, $plclong, $plccat, $plcid;

class Place
{

    private $pname;
    private $paddr;
    private $pcity;
    private $pstate;
    private $plat;
    private $plong;
    private $prating;

    function getAllPlaces()
    {

        $plcqry = "SELECT * FROM place,state,city where place.st_id = state.st_id AND place.ct_id = city.ct_id";
        $rows = mysql_query($plcqry);
        return mysql_fetch_assoc($rows);

        /*
        while($res = mysql_fetch_assoc($rows))
        {
            $GLOBALS["plcname"] = $res["plc_nm"];
            $GLOBALS["plcstate"] = $res["st_nm"];
            $GLOBALS["plccity"] = $res["ct_nm"];
            echo $GLOBALS["plcname"]." -- ".$GLOBALS["plccity"]." -- ".$GLOBALS["plcstate"]."<br><br>";
        }
         * */

    }

    function getPlace($name, $city, $state)
    {

        $this->pname = $name;
        $this->pcity = $city;
        $this->pstate = $state;

        $row = mysql_query($plcqry);
        $plcqry = "SELECT place.plc_nm, place.plc_photo, place.plc_addr, place.ct_id, place.plc_lat, place.plc_long, city.ct_nm, state.st_nm FROM place,state,city WHERE place.plc_nm = '".$this->pname."' AND place.st_id = state.st_id AND state.st_nm = '".$this->pstate."' AND place.ct_id = city.ct_id AND city.ct_nm = '".$this->pcity."'";

        @$row = mysql_query($plcqry);

        $res = mysql_fetch_assoc($row);

        $GLOBALS["plcname"] = $res["plc_nm"];
        $GLOBALS["plcaddr"] = $res["plc_addr"];
        $GLOBALS["plccity"] = $res["ct_nm"];
        $GLOBALS["plcstate"] = $res["st_nm"];
        $GLOBALS["plcpic"] = $res["plc_photo"];
        $GLOBALS["plclat"] = $res["plc_lat"];
        $GLOBALS["plclong"] = $res["plc_long"];

        //echo "".$GLOBALS["plcname"]."<br>";// <img src=\"".$GLOBALS["plcpic"]."\"/>";
    }

    function ratePlace($name,$city,$state,$rating)
    {        

        $this->pname = $name;
        $this->pcity = $city;
        $this->pstate = $state;
        $this->prating = $rating;

        $plcqry = "SELECT place.plc_id, place.plc_rating FROM place,state,city WHERE place.plc_nm = '".$this->pname."' AND place.st_id = state.st_id AND state.st_nm = '".$this->pstate."' AND place.ct_id = city.ct_id AND city.ct_nm = '".$this->pcity."'";
        $row = mysql_query($plcqry);
        $res = mysql_fetch_assoc($row);
        $GLOBALS["plcrating"] = $res["plc_rating"];
        $GLOBALS["plcid"] = $res["plc_id"];

        $rating += $GLOBALS["plcrating"];

        $ratingqry = "UPDATE place SET plc_rating = ".$this->prating." WHERE plc_id = ".$GLOBALS["plcid"]."";
        mysql_query($ratingqry);

        $plcqry = "SELECT plc_rating FROM place WHERE plc_id = ".$GLOBALS["plcid"]."";
        $row2 = mysql_query($plcqry);
        $res2 = mysql_fetch_assoc($row2);
        $GLOBALS["plcrating"] = $res2["plc_rating"];    
    }

    function getPlaceByRegion($city, $state)
    {
        $this->pcity = $city;
        $this->pstate = $state;

        $plcqry = "SELECT place.plc_id, place.plc_nm, state.st_nm, city.ct_nm FROM place,state,city WHERE place.st_id = state.st_id AND state.st_nm = '".$this->pstate."' AND place.ct_id = city.ct_id AND city.ct_nm = '".$this->pcity."'";
        $rows = mysql_query($plcqry);

        while($res = mysql_fetch_assoc($rows))
        {

            $GLOBALS["plcname"] = $res["plc_nm"];
            $GLOBALS["plcstate"] = $res["st_nm"];
            $GLOBALS["plccity"] = $res["ct_nm"];
            //echo $GLOBALS["plcname"]." -- ".$GLOBALS["plccity"]." -- ".$GLOBALS["plcstate"]."<br><br>";
        }
    }
}

?>

    //And this is the other part of the code, which I use in another PHP file that
    //contains the HTML code ("view layer"). File name is "displayplaces.php"
    <?php
        include './placeops.php';
        $obj = new Place;

        $res = $obj->getAllPlaces();
        while (next($res))
        {
          //expected string parameter errors for all these assignments
          $GLOBALS["plcname"] = current($res["plc_nm"]);
          $GLOBALS["plcstate"] = current($res["st_nm"]);
          $GLOBALS["plccity"] = current($res["ct_nm"]);
          $GLOBALS["plcrating"] = current($res["plc_rating"]);
          $GLOBALS["plclat"] = current($res["plc_lat"]);

          echo "<tr>
                  <td>" . $GLOBALS["plcname"] . "</td>
                  <td>" . $GLOBALS["plcrating"] . "</td>
                  <td>" . $GLOBALS["plccity"] . "</td>
                  <td>" . $GLOBALS["plcstate"] . "</td>
                  <td>" . $GLOBALS["plclat"] . "</td>
               </tr>";
        }

    ?>

目前表中有14条记录。我知道我可以通过在“displayplaces.php”文件本身中编写 sql 处理代码来解决这个问题。但功能和显示逻辑是否可以保持不同呢？可以在 $res 数组中使用额外的索引吗？或者我是否必须在显示内容的同一个 PHP 页面中编写获取代码？

Answer 1

这里使用对象存在一些问题。首先，这实际上并不是面向对象的。您可以在不使用全局变量的情况下完成此操作 - 对象应在内部包含其数据。

我希望名为 Place 的类仅包含一个地点，但您提供了一种名为 getPlaces 的方法，该方法似乎不符合该目的。我建议您创建另一个名为 PlaceSet 的类(或类似的复数形式)，其中包含数组中的多个 Place 对象。

类似这样的事情:

class Place {
    // I've stored some example properties here, you can
    // change these if you wish
    protected $id;
    protected $name;
    protected $state;
    protected $city;

    // I've used a constructor here, but you could use a setter function
    // instead, so that a Place can have its properties changed during its
    // lifetime
    public function __construct($id, $name, $state, $city) {
        $this->id = $id;
        $this->name = $name;
        $this->state = $state;
        $this->city = $city;
    }

    public function ratePlace($rating) {
        // You can access $this->id to set a rating
    }

    // Offer getters in this format
    public function getName() {
        return $this->name;
    }
}

class PlaceSet {
    // This function just returns an array of Places, but you could
    // also store that result in this class if you wish, so as to
    // reuse it without having to rerun the query every time
    public function getAllPlaces() {
        // Word-wrap your long lines!
        $plcqry = "
            SELECT *
            FROM place,state,city
            WHERE
                place.st_id = state.st_id
                AND place.ct_id = city.ct_id
        ";
        // @todo This legacy library needs to be swapped out
        $rows = mysql_query($plcqry);

        $places = array();
        while($res = mysql_fetch_assoc($rows))
        {
            $places[] = new $Place(
                $res["plc_id"]
                $res["plc_nm"],
                $res["st_nm"],
                $res["ct_nm"]
            );
        }

        return $places;
    }

    // Maybe this should be getPlacesByRegion?
    //
    // Always declare your access level
    public function getPlaceByRegion($city, $state)
    {
        // Add code here
    }

}

您可以通过以下方式访问完整的地点列表:

<?php
    // Do your connection here

    include './placeops.php';
    $placeSet = new PlaceSet();

    $places = $placeSet->getAllPlaces();
    foreach ($places as $place) {
        // Add these getters into the Place class
        echo "<tr>
              <td>" . $place->getName() . "</td>
              <td>" . $place->getRating() . "</td>
              <td>" . $place->getCity() . "</td>
              <td>" . $place->getState() . "</td>
              <td>" . $place->getLat() . "</td>
           </tr>";
    }

?>