如何在 html 中使用 select 标签来选择特定的 sqlite3 查询与 php？

如何解决如何在 html 中使用 select 标签来选择特定的 sqlite3 查询与 php？

我尝试过的是使用 if 语句和 switch 语句，但它仍然无法正常工作，因为它进入默认值：“出错了”，我已经编码了，但我不确定出了什么问题

<form action="index.PHP" method="post" id="formSelect">
        
            <div id="chosen">
            
            <label for="pkCountry" class="blue">Choose a country:</label>
            
            <select name="chooseCountry" id="choose">
                
                <option value="start">select...</option>
                <option value="Australia">Australia</option>
                 <option value="India">India</option>
                 <option value="Pakistan">Pakistan</option>
                 <option value="England">England</option>
                 <option value="South Africa">South Africa</option>
                 <option value="Sri Lanka">Sri Lanka</option>
                 <option value="Bangladesh">Bangladesh</option>
                 <option value="West Indies">West Indies</option>
            
            </select>
                
                <?PHP
                 $db = new sqlite3('cricket.db');

                        if (!$db) {
                             echo $db->lastErrorMsg();
                           } 
                       else {
                            switch (isset($_POST['formCountry'])){
                              case 'India':
                              $command = $db->query("SELECT * FROM batsman WHERE country = 'India';");
                              
                              $db->exec($command);
                                  
                            break;
                              case 'Australia':
                               $command1 = $db->query("SELECT * FROM batsman WHERE country = 'Australia';");
                              
                              $db->exec($command1);
                                  
                            break;
                                  
                              case 'England':
                                  $command2 = $db->query("SELECT * FROM batsman WHERE country = 'England';");
                              
                              $db->exec($command2);
                                  
                            break;
                                  
                              case 'Pakistan':
                                  $command3 = $db->query("SELECT * FROM batsman WHERE country = 'Pakistan';");
                              
                                  $db->exec($command3);
                                  
                            break;
                                  
                              case 'Bangladesh':
                                  $command4 = $db->query("SELECT * FROM batsman WHERE country = 'Bangladesh';");
                              
                                 $db->exec($command4);
                            break;
                                  
                             case 'Sri Lanka' :
                                  $command5 = $db->query("SELECT * FROM batsman WHERE country = 'Sri Lanka';");
                              
                                  $db->exec($command5);
                                  
                           break;
                                  
                              case 'South Africa':
                                 $command6 = $db->query("SELECT * FROM batsman WHERE country = 'South Africa';");
                              
                                 $db->exec($command6);
                                  
                                break;
                                  
                              case 'West Indies':
                                  $command7 = $db->query("SELECT * FROM batsman WHERE country = 'West Indies';");
                              
                                  $db->exec($command7);
                                break;
                              default:
                                  echo "<br>something went wrong</br>";                                 
                                  $db->close();
                                 
                                  
                          }  
                             
                
                        
                        
                        }
                        
                ?>

解决方法

您在寻找chooseCountry时选择的名称是$_POST['formCountry']

您应该将您的开关更新为

switch ($_POST['chooseCountry']){

此外，isset 函数仅返回布尔值、true 或 false。您不能在交换机中使用它。如果想避免警告，需要在switch前加一个if

if(isset($_POST['chooseCountry'])) {
    switch ($_POST['chooseCountry']){
        // CODE
    }
}