take a value from a select option and use it on php

Question

I have this select , i wanna save each value after change , save it and use in other select

This is my code :

<?
$sql = "SELECT * FROM championnat ";
$result = $conn->query(sprintf($sql));
if($result){
    if ($result->num_rows != 0)
    {  
        $rows=array(); 
?>
<select name="nom_championnat" id="nom_championnat" >
    <option value=""></option>
    <?php
        while($r=mysqli_fetch_assoc($result))
        { 
    ?>
    <option   value=" <?php echo $r['idChampionnat']?>" name="nom_championnat" selected >
    <?php  echo $r['nomChampionnat']  ?></option>
    <?php
        }
    }
}
?>
</select>
</div>

I need the variable $r['idChampionnat'] to save it in each select and use it in this requete , how can it asve and put it in that requete sql ????

<?php
$sql = "SELECT * FROM equipe  where idChampionnat=???? ";
$result = $conn->query(sprintf($sql));
if($result){
    if ($result->num_rows != 0)
        {
        $rows=array(); 
?>
<select name="equipe1" >
    <option value=""></option>
    <?php
        while($r=mysqli_fetch_assoc($result))
        { 
    ?>
    <option  required value=" <?php echo $r['nomEquipe']?>" name="equipe1" selected ><?php  echo $r['nomEquipe']  ?>
    </option>
    <?php
        }
    }
}
?>
</select>

just to clear it ,

you need to populate the 2nd select by using an AJAX call which queries your database based on the value of the first, then updates the options of the 2nd based on the returned result. — DevDonkey, Apr 08 '16 at 12:28

score 1 · Accepted Answer · edited May 23 '17 at 11:45

You need to use jQuery to fire an AJAX call when the first box is selected.

Its been a while since I've done this but this should give you some idea. I took some code from here and here as example

Say your html looks like this

<select id="nom_championnat">
    <option value="value1">value1</option>
    <option value="value2">value2</option>
</select>
<select id="equipe1"></select>

then you need to tell jquery what to do when nom_championnat changes selection

$('#nom_championnat').change(function() {
    var data = "";
    $.ajax({
        type:"POST",
        url : "queryfile.php",
        data : "value="+$(this).val(),
        async: false,
        success : function(response) {
            data = response;
            return response;
        },
        error: function() {
            alert('Error occured');
        }
    });
    var string = data.message.split(",");
    var array = string.filter(function(e){return e;});
    var select = $('equipe1');
    select.empty();
    $.each(array, function(index, value) {          
        select.append(
                $('<option></option>').val(value).html(value)
            );
    });
});

and then you need a queryfile.php to handle the ajax requests, something like

<?php 
   print_r($_POST);
   $value = $_POST["value"];
   $sql = "select where {$value} ..."
   $result = execute($sql);
   echo $result;
?>

take a value from a select option and use it on php

1 Answers1