passing values from selected option in form - php

Question

<form method="post">
<div class="form-group">
<label >Product</label>
<select class="form-control" name="product" id="supplier-select" >
<option value="">Select a Product </option>
<?php
$link = mysqli_connect();
if (!$link) {
die('Could not connect: ' . mysqli_connect_error());
}
$query="select id,name from product";
$result = mysqli_query($link,$query);
while($row = mysqli_fetch_array($result)){
echo "<option value=".$row['id']."name='product' >".$row['name']."</option>";
}
?></select>
</div>
<div class="form-group">
<label >Date</label>
<input type="date" name="date" class="form-control" id="" >
</div>
<div class="form-group">
<label >Sale Quantity</label>
<input type="text" name="quantity" class="form-control" id="">
</div>
<div class="form-group">
<label >Sale Price</label>
<input type="text" name="price" class="form-control" id="">
</div>
<button type="submit" class="btn btn-primary">Submit</button>
</form>
<?php
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
$id = $_POST['id'];
$product = $row['product'];
$date =$_POST['date'];
$quan = $_POST['quantity'];
$price = $_POST['price'];
$link= mysqli_connect();
if(!$link){
die ('connection unsuccessful'. mysqli_connect_error($link));
}
$sql = "INSERT INTO items_sale (sale_id, prod_id, date, sale_quantity, sale_price) VALUES ('$id','$product','$date','$quan','$price')";
if (mysqli_query($link, $sql)) {
exit();
} else {
echo "Error: " . $sql . "<br>" . mysqli_error($link);
}
how do I pass in value from selected option from to insert query in this code here. i have using row[] but the value is not passing on in the from to my insert query when I selected. in past i have tried POST['id'] but it select the same value as the id before.

Answer 1

Try changing line
echo "<option value=".$row['id']."name='product' >".$row['name']."</option>";
to
echo "<option value=".$row['id'].">".$row['name']."</option>"
$row['product'] doesn't exist - try changing the beginning of your php code to
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
$id = $_POST['id'];
$product = $_POST['product'];
...