PHP中的动态Optgroup

Question

This is my current SQL Table I'm using to grab data for my php dropdown. The main goal of this is to turn this into a dropdown that has an optgroup with the members below and so on...

 +-----------+------------+-----------+ | GroupName | MemberName | ValueName | +-----------+------------+-----------+ | 1st Team | Joe Bob | Joe | | 1st Team | Catherine | Kat | | 2nd Team | Tommy | Tom | | 3rd Team | John Razks | John | +-----------+------------+-----------+ Table name: Members 

Basically at the end result is such of the code below. It will be a dropdown with an optgroup called "1st Team" and have the members below ect. for 2nd Team and 3rd Team and so on.

 <optgroup class="1st Team"> <option value="Joe">Joe Bob</option> <option value="Kat">Catherine</option> </optgroup> <optgroup class="2nd Team"> <option value="Tom">Tommy</option> </optgroup> <optgroup class="3rd Team"> <option value="John">John Razks</option> </optgroup> 

Right now, this is how I get information from my SQL table. This works fine, but if I want to add a new GroupName then I would have to add a new code to my main page and I don't want to do that.

Trying make it dynamic so if the SQL table gets updated with a new GroupName, then a new optgroup class will appear in the dropdown and the members will be below.

 <optgroup class="1st Team"> <?php $conn = mysqli_connect("#connect_to_sql"); if(!$conn){ die("Connection Failed".myslqi_connect_error()); } $result = mysqli_query($conn, "SELECT distinct MemberName from Members where GroupName = "1st Team" order by MemberName ASC"); while ($row = mysqli_fetch_assoc($result)){ unset($membername, $groupname); $groupname = $row['GroupName']; $membername = $row['MemberName']; echo '<option value="'.$membername.'">'.$membername.'</option>'; } ?> </optgroup> 

I'm not positive at all on what to do. I've looked at other people's examples, but not sure how to approach this step.

Answer 1

It's not the most elegant way, but you could build your group this way, what it's doing is checking the name of the group and changes that to a new optgroup each time the name changes, the $first var is just there so it doesn't add a closing tag the first time around.

I'm sure you can improve on this, but it should get you going.

It does kind of rely on a consistent naming convention for the group name, so as I say, I'm sure you could improve on it. I've also not included the connection checks as you've done that already in your example

$result = mysqli_query($conn, "SELECT * FROM Members ORDER BY GroupName");
$groupName = '';
$first = true;
echo '<select>';
while ($row = mysqli_fetch_assoc($result)){
    if ($row['GroupName'] != $groupName) {
        $groupName = $row['GroupName']; // Just set the new group name
        if (!$first) { // Add a closing tag when we change the group, but only if we're not in the first loop
            echo '</optgroup>';
        } else {
            $first = false; // Make sure we don't close the tag first time, but do after the first loop
        }
        echo '<optgroup label="' . $groupName . '">';
    }
    // We want to echo the options every loop so it's outside the if condition
    echo '<option value="' . $row['MemberName'] . '">' . $row['ValueName'] . '</option>';
}
echo '</select>';

Answer 2

First get all records from the database. create an array with keys as group name. Loop the new array to generate the desired output.

// query to get all records from database table
$result = mysqli_query($conn, "SELECT distinct MemberName,GroupName,ValueName from Members order by MemberName ASC");
while ($row = mysqli_fetch_assoc($result)){
    // generate an array with keys as group name
    $array[$row['GroupName']][] = $row;
}

// loop the array to create optgroup
foreach($array as $key=>$value){
    // check if its an array
    if(is_array($value)){
        // create optgroup for each groupname
        echo "<optgroup class='".$key."'>";
        foreach($value as $k=>$v){
            echo "<option value='".$v['membername']."'>'".$v['membername']."'</option>";
        }
        echo "</optgroup>";
    }
}

I have not tested this but sure this will help you. And you can make improvements.