dqpdb82600 2019-05-21 23:16
浏览 98

下拉搜索列表无法获取等于所选选项的变量

I have this dropdown list that shows the name of different conferences. I can select a certain conference, but as I select the conference, I want to add a submit button so I can get a variable for the conference that was selected.

I'm new with databases, but I have tried adding a form, but I can't seem to get it to work inside of the php code. The database connects and shows all of the conferences just fine, I just can't figure out how to get a variable equal to the selected option.

<!DOCTYPE HTML>  
<html>
<head>
<style>
.error {color: #FF0000;}
</style>
</head>
<body>  

<?php
//Declare variables
$db_host = "";
$db_username = "";
$db_pass = "";
$db_name = "";
$db_table = "";
//Connect to phpMyAdmin
$con=mysqli_connect("$db_host","$db_username","$db_pass","$db_name");

// Check connection
if (mysqli_connect_errno())
  {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
  }

mysqli_select_db($con,"$db_name") or die ("No database");

$result=mysqli_query($con,"select * From conferenceList");

echo "<select id='searchddl'>";
echo "<option> -- Search Conference Name -- </option>";
while($row=mysqli_fetch_array($result))
{
    echo "<option>$row[name]</option>";
}
echo "</select>";


//Close phpMyAdmin
mysqli_close($con);
?>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/chosen/1.8.7/chosen.jquery.min.js"></script>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/chosen/1.8.7/chosen.min.css" />

<script>
    $("#searchddl").chosen();
</script>

</body>
</html>

I expected a variable to equal the same thing that is selected. So I want my variable to equal whatever this is echo "<option>$row[name]</option>"; enter image description here

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1条回答 默认 最新

  • dongtao1262 2019-05-21 23:45
    关注
    <script>
    $( "#searchddl" ).chosen().change(function() {  // execute query every time select option changes
    var val = $( "#searchddl" ).chosen().val();  // get value from selected option
    $.ajax({
        url: "myphpfile.php", // call external PHP file for query execution
        type: "get", 
        data: { 
            myselectvalue: val // passes value as GET parameter (?=myselectvalue=val) 
        },
        success: function(response) {
            tmp = response // store variable from PHP output
            // do Something

        },
        error: function(xhr) {
             // do Something else
        }
    });
</script>

    In your a separate PHP file you can get the value from the get variable:

    if (isset($_GET['myselectvalue']) && strlen($_GET['myselectvalue']) { // make sure it's populated

    $valueFromForm = $_GET['myselectvalue'];

    // Execute queries, echo results, etc.

}

    I used GET in this solution but POST would work as well. You would just need to change type: "get" to type: "post" in the ajax call and $_GET[] to $_POST[] in the PHP.

    评论

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