PHP Why does my select option show empty - php

Question

When I submit the form I don't get the value of the select option I tried using POST and session but it always show nothing
main.php
<form role="form" method="POST" action="test.php">
<?php if($id == 1 OR $id==2){
echo" <p> No data</p> ";}else{
?>
<select class="form-control" name="data">
<?php
$getdata = "SELECT * FROM tbl_data";
$data = mysqli_query($conn,$getdata )
or die(mysqli_error());
while ($row=mysqli_fetch_assoc( $data )) {
$dataName = $row['data_name'];
echo '<option value="'.$row['data_id'].'">'.$dataName.'</option>';
$_SESSION['data_id']= $data_id;
}
?>
</select>
<button type="submit" class="btn btn-primary">show</button>
</form>
test.php
$dataID = isset($_POST['data_id']) ? $_POST['data_id'] : '';
echo "data is $dataID";

Answer 1

Name of your input type select is data and you are accessing it with data_id so you have to use $_POST['data'] instead of $_POST['data_id']

Answer 2

get value of select box using name "data" as you have set name="data" in <select> box in html:
$dataID = isset($_POST['data']) ? $_POST['data'] : '';
echo "data is".$dataID;

Answer 3

main.php
<form role="form" method="POST" action="test.php">
<?php
if($id == 1 OR $id==2)
{
echo" <p> No data</p> ";
}
else
{
?>
<select class="form-control" name="data">
<?php
$getdata = "SELECT * FROM tbl_data";
$data = mysqli_query($conn,$getdata ) or die(mysqli_error());
while ($row=mysqli_fetch_assoc( $data ))
{
$dataName = $row['data_name'];
echo '<option value="'.$row['data_id'].'">'.$dataName.'</option>';
}
?>
</select>
<?php
}
?>
<button type="submit" class="btn btn-primary">show</button>
test.php
$dataID = isset($_POST['data']) ? $_POST['data'] : '';
echo "data is $dataID";
try this one..

Answer 4

Check below points its may be creating issue.
Check first your <select class="form-control" name="data"> name is data so you can access it using $_POST['data'] not data_id.
Check for <option value="'.$row['data_id'].'"> may be data_id not giving correct value try to check with static value.

Answer 5

I modified this code for you,please use this code.Its work for me,i hope this code will work also for you.
main.php
<form role="form" method="POST" action="test.php">
<?php
if($id == 1 OR $id==2)
{
echo" <p> No data</p> ";
}
else
{
?>
<select class="form-control" name="data">
<?php
$getdata = "SELECT * FROM tbl_data";
$data = mysqli_query($conn,$getdata ) or die(mysqli_error());
while ($row=mysqli_fetch_assoc( $data ))
{
$dataName = $row['data_name'];
?>
<option value="<?php echo $row['data_id']; ?>"><?php echo $dataName ?></option>
$_SESSION['data_id']= $row['data_id'];
<?php
}
}
?>
</select>
<button type="submit" class="btn btn-primary">show</button>
</form>
test.php
<?php
if(isset($_POST['data']))
{
echo $_POST['data'];
}
?>