PHP foreach 将所有内容输出四次（mysql、sql、数据库管理）答案

【问题标题】：PHP foreach outputs everything four times (mysql, sql, database administration)PHP foreach 将所有内容输出四次（mysql、sql、数据库管理）
【发布时间】：2015-04-22 13:44:09
【问题描述】：

我在这里有一些代码，我觉得可以提高效率。我一直在构建一个图书馆目录数据库，并且正在寻找一种方法来将从 SQL 数据库中提取的多个列（具有多个条目）存储到一个 PHP 数组中。这意味着在“视图”代码中只需要一个 foreach 循环来打印结果并将它们存储在表中。你们中的任何人都有有用的想法吗？ :)

我当前状态的代码如下：

MODEL CODE:

$matches["loandates"] = array();
        $matches["loanduedates"] = array();
        $matches["itemnames"] = array();
        $matches["itemauthors"] = array();

        try { // if we do find an item, then we run this query against the database to get a list of all the current loans.
            $results = $db->prepare("
                SELECT il.loan_date, il.loan_duedate, i.item_name, i.item_author 
                FROM itemloan il 
                INNER JOIN libraryitem li
                ON il.libraryItem_id = li.libraryItem_id
                INNER JOIN item i
                ON li.item_id = i.item_id
                WHERE il.user_id = ?
                ORDER BY il.loan_date asc
                    ");
            $results->bindParam(1,$userid); // puts user id value where the placeholder is. First value is character of placeholder, second value is variable we want to bind to placeholder).
            $results->execute();
            } catch (Exception $e) {
                echo "Data could not be retrieved from the database.";
                exit;
            }

             while ($row = $results->fetch(PDO::FETCH_ASSOC)) { // we loop through the loans one at a time, and add them to our matches variable
                $matches["loandates"][] = $row["loan_date"];

                $matches["loanduedates"][] = $row["loan_duedate"];

                $matches["itemnames"][] = $row["item_name"];

                $matches["itemauthors"][] = $row["item_author"];

            }

          return $matches;                  
    }

查看代码：

<table id="name">

                    <?php 
                                    foreach($user["itemnames"] as $itemname) { 

                                            echo "<tr><td id='radiocell'><input type='radio' name='libraryitemid' id='radio'></td><td class='user'>" . $itemname . "</td></tr>";
                                            }
                    ?>

                </table>

                <table id="author">
                    <?php

                                    foreach($user["itemauthors"] as $itemauthor) {

                                            echo "<tr><td class='user'>" . $itemauthor . "</td></tr>";

                                            }
                            ?>

                </table>

                <table id="date">
                    <?php



                                    foreach($user["loandates"] as $loandate) {

                                            $time = strtotime($loandate);
                                            $myFormatForView = date("l d F Y", $time);

                                            echo "<tr><td class='user'>" . $myFormatForView  . "</td></tr>";

                                            }
                            ?>

                </table>

                <table id="duedate">
                    <?php

                                    foreach($user["loanduedates"] as $loanduedate) {

                                            $time = strtotime($loanduedate);
                                            $myFormatForView = date("l d F Y", $time);

                                            echo "<tr><td class='user'>" . $myFormatForView . "</td></tr>";

                                            }
                            ?>

                </table>

我最终只想要一个带有一个 foreach 循环的表，而不是四个带有四个 foreach 循环的表。如果你明白我的意思。

如果有人能提供帮助，我将不胜感激！提前致谢！！

问候，

罗伯特，英国伦敦

【问题讨论】：

P.S.数据库选择的结果（在模型代码中）都存储在一个名为 $user 的变量中。

标签： php html mysql foreach

【解决方案1】：

 $matches[] = array("loandates" => $row["loan_date"],
               "loanduedates" => $row["loan_duedate"],
                "itemnames" => $row["item_name"],
                "itemauthors" => $row["item_author"]);

现在你有了一个数组，你可以用一个 foreach 来显示它。

foreach($matches as $match) {
   echo $match['loandates'] . '</td><td>' . $match['loan_duedate'] ...

【讨论】：

【解决方案2】：

while ($row = $results->fetch(PDO::FETCH_ASSOC)) { // we loop through the loans one at a time, and add them to our matches variable
     $matches[] = $row;
 }

然后：

<table id="name">

<?php 
    foreach($user as $key=>$values) { 
       echo '<tr>';
       foreach($values as $itemname) {
        //echo <td> with data
       }
       echo '</tr>';
    }

【讨论】：