Question

我试图在php页面中进行图形更改，具体取决于mySQL数据库查询的结果。

<?php
$find_howto=mysql_query("SELECT * FROM `answers` WHERE `username`='$username' AND `pagename`='_I1' ORDER BY `answer` DESC") or die("Error fetching course selection, How To Use The Course");
if(mysql_num_rows($find_howto)>=1)
{   
$howto_data=mysql_fetch_assoc($find_howto);
if($howto_data['answer'] == "yes")
{
$count="red";
}elseif($howto_data['answer'] == "visited")
{
$count="yellow";
}
$find_quiz=mysql_query("SELECT * FROM `answers` WHERE `username`='$username' AND `pagename`='_I2' ORDER BY `answer` DESC") or die("Error fetching course selection, Quick Quiz");
if(mysql_num_rows($find_quiz)>=1)
{   
$quiz_data=mysql_fetch_assoc($find_quiz);
if($quiz_data['answer'] == "yes")
{
$count="red";
}elseif($quiz_data['answer'] == "visited")
{
$count="yellow";
}
}

if($count == "red")
{
echo '<img name="Introduction" border="0" src="../img/directories/main/IntroductionRed.gif" width="250" height="18"></a></td>';
}elseif($count == "yellow")
{
echo '<img name="Introduction" border="0" src="../img/directories/main/IntroductionYellow.gif" width="250" height="18"></a></td>';
}else{
echo '<img name="Introduction" border="0" src="../img/directories/main/IntroductionGreen.gif" width="250" height="18"></a></td>';
}
?>

如果第一个查询的结果是“是”，那么我给“count”变量赋值“red”。

如果第一个查询的结果是“访问过”，那么我给“count”变量赋值“yellow”。

逻辑可能是正确的，但编码错误。

如何让“if / elseif / else”在上面工作？我实际上有10块可以使用，而不仅仅是两块。但如果这样可行，我可以添加其余部分。

更新的解决方案：好的。我设法以不同的方式做到了（有很多帮助）：

<?php
$find_intro_comp=mysql_query("SELECT * FROM `answers` WHERE `username`='$username' AND (`pagename`='_I1' OR `pagename`='_I2' OR `pagename`='_I3' OR `pagename`='_I4' OR `pagename`='_I5' OR `pagename`='_I6' OR `pagename`='_I7' OR `pagename`='_I8' OR `pagename`='_I9' OR `pagename`='_I10') AND `answer`='yes'") or die("Error pulling intro completed");
if(mysql_num_rows($find_intro_comp)>=10) // the number 10 depends on how many pages there are.
{
    echo '<img name="Introduction" border="0" src="../img/directories/main/IntroductionRed.gif" width="250" height="18"></a></td>';
}else{
$find_intro_visit=mysql_query("SELECT * FROM `answers` WHERE `username`='$username' AND (`pagename`='_I1' OR `pagename`='_I2' OR `pagename`='_I3' OR `pagename`='_I4' OR `pagename`='_I5' OR `pagename`='_I6' OR `pagename`='_I7' OR `pagename`='_I8' OR `pagename`='_I9' OR `pagename`='_I10') AND `answer`='visited'") or die("Error pulling intro visited");
if(mysql_num_rows($find_intro_visit)>=1)
    {
        echo '<img name="Introduction" border="0" src="../img/directories/main/IntroductionYellow.gif" width="250" height="18"></a></td>';
    }else{
        echo '<img name="Introduction" border="0" src="../img/directories/main/IntroductionGreen.gif" width="250" height="18"></a></td>';
    }
}
?>

Answer 1

你最后错过了}。另外，请在代码中添加适当的选项卡序列，以便更好地使用任何IDE。

$find_howto = mysql_query("SELECT * FROM `answers` WHERE `username`='$username' AND `pagename`='_I1' ORDER BY `answer` DESC") or die("Error fetching course selection, How To Use The Course");
if (mysql_num_rows($find_howto) >= 1) {
    $howto_data = mysql_fetch_assoc($find_howto);
    if ($howto_data['answer'] == "yes") {
        $count = "red";
    } elseif ($howto_data['answer'] == "visited") {
        $count = "yellow";
    }
    $find_quiz = mysql_query("SELECT * FROM `answers` WHERE `username`='$username' AND `pagename`='_I2' ORDER BY `answer` DESC") or die("Error fetching course selection, Quick Quiz");
    if (mysql_num_rows($find_quiz) >= 1) {
        $quiz_data = mysql_fetch_assoc($find_quiz);
        if ($quiz_data['answer'] == "yes") {
            $count = "red";
        } elseif ($quiz_data['answer'] == "visited") {
            $count = "yellow";
        }
    }

    if ($count == "red") {
        echo '<img name="Introduction" border="0" src="../img/directories/main/IntroductionRed.gif" width="250" height="18"></a></td>';
    } elseif ($count == "yellow") {
        echo '<img name="Introduction" border="0" src="../img/directories/main/IntroductionYellow.gif" width="250" height="18"></a></td>';
    } else {
        echo '<img name="Introduction" border="0" src="../img/directories/main/IntroductionGreen.gif" width="250" height="18"></a></td>';
    }
}

Answer 2

您必须使用while循环从数据库中获取所有结果，然后您可以使用带有已获取值的嵌套if else检查

Answer 3

我建议您从SQL查询中删除AND pagename ='_I2'部分（使代码更加笨重，对SQL服务器进行多次重复查询）

您还可以通过在SQL查询中指定PHP逻辑来跳过它（见：http://dev.mysql.com/doc/refman/5.0/en/case.html）

看起来像编号所以orderby pagename应该没问题

Answer 4

你应该在街区上方宣布计数而你错过了一个}支架..

  <?php

  $count;
$find_howto=mysql_query("SELECT * FROM `answers` WHERE `username`='$username' AND `pagename`='_I1' ORDER BY `answer` DESC") or die("Error fetching course selection, How To Use The Course");
if(mysql_num_rows($find_howto)>=1)
{   
$howto_data=mysql_fetch_assoc($find_howto);
if($howto_data['answer'] == "yes")
{
$count="red";
}elseif($howto_data['answer'] == "visited")
{
$count="yellow";
}
}//
$find_quiz=mysql_query("SELECT * FROM `answers` WHERE `username`='$username' AND `pagename`='_I2' ORDER BY `answer` DESC") or die("Error fetching course selection, Quick Quiz");
if(mysql_num_rows($find_quiz)>=1)
{   
$quiz_data=mysql_fetch_assoc($find_quiz);
if($quiz_data['answer'] == "yes")
{
$count="red";
}elseif($quiz_data['answer'] == "visited")
{
$count="yellow";
}
}

if($count == "red")
{
echo '<img name="Introduction" border="0" src="../img/directories/main/IntroductionRed.gif" width="250" height="18"></a></td>';
}elseif($count == "yellow")
{
echo '<img name="Introduction" border="0" src="../img/directories/main/IntroductionYellow.gif" width="250" height="18"></a></td>';
}else{
echo '<img name="Introduction" border="0" src="../img/directories/main/IntroductionGreen.gif" width="250" height="18"></a></td>';
}
?>

在PHP中嵌套if else语句

4 个答案: