PHP - Capture Html Data Between Tags

I have a navigation list displaying which is a mix of html and php, everything is working fine however now I want to convert this block of code into a function but am having major problems with quotes.

The line of code I currently have is 

$data = $db->query("SELECT * FROM menu")->fetchAll(PDO::FETCH_ASSOC);

foreach ($data as $row) { ?>
     <li><a href="<?php echo $row['url']; ?>" title="<?php echo $row['title']; ?>"><?php echo $row['icon'] . ' ' . $row['header']; ?></a></li>

<?php
	}
?>

As I say everything works using the above but now I am trying to echo the full li out and am having major issues with single and double quotes.

I currently have 

echo "<li><a href='#' title='the title'><i class='fas fa-user site-nav--icon'></i> Help</a></li>";

Now I am trying to use the $row['url'], $row['title'], $row['icon'] & $row['header'] as per the top example but I cannot get the combination of quote marks correct, whether to use double, single or a combination.

I would be grateful if someone could suggest the correct syntax for the a tag then I can work through the rest.

Thanks

I am adding line items in my invoice script, while adding i validate the data. if validation fails, it will display error message with entered data filled in the form. If it clears the validation, data gets submitted to database and displays the same . Here i can add many line items, so this process should keep repeating.

Everything is working fine. But when the form submits it should display error in one place and display the submitted data in other place.

Here is my form

<form action="" method="post">
                                        <div class="form-row">
                                            <div class="col-md-4 mb-30">
                                                <label for="validationDefault01">Select Customer</label>
                                            <select name="customer" class="form-control" id="validationDefault01" required>
                                            <option value=""></option>
                                            <?php $c1 = mysqli_query($con, "SELECT * FROM customers WHERE status='Active'") or die (mysqli_error($con));
                                            while($c2 = mysqli_fetch_array($c1))
                                            {
                                                ?>
                                           
                                            <option value="<?php echo $c2["cid"]; ?>" <?php if($c2["cid"] == $_POST['customer'] ) { echo "selected"; }  ?> ><?php echo $c2["name"]; ?></option>
                                            <?php } ?>
                                            </select>    
                                            </div>

 
  <div class="col-md-4 mb-30">
  <label for="validationDefault02">Date</label>
 <input type="text" class="form-control" name="edate" id="datepicker" value="<?php echo isset($_POST["edate"]) ? $_POST["edate"] : $today; ?>" required />  
  </div>
  </div>                               
<!-- line item -->                               
                               <div class="table-responsive">
                             <table class="table table-active table-bordered table-sm">
                             <thead class="thead-active">

                              <tr>
                             <th>Name</th>
                            <th>Description</th>
                            <th>UOM</th>    
                            <th>Price</th>
                            <th>Stock</th>
                            <th>Qty</th>  
                            </tr>
                           </thead> 
                            <tr> 
  <td><input type="text"  id="productname" name="productname" value="<?php echo isset($_POST["productname"]) ? $_POST["productname"] : ''; ?>" required ></td> 
                               <input type="hidden"  id="productcode" name="productcode" value="<?php echo isset($_POST["productcode"]) ? $_POST["productcode"] : ''; ?>"  />
                                <td><textarea id="description" name="description"><?php echo isset($_POST["description"]) ? $_POST["description"] : ''; ?></textarea></td>
                                
                           
                                <td><select name="uom" id="uom">
                               
                                <?php $su1 = mysqli_query($con, "select * from uom");  while($su2 = mysqli_fetch_array($su1)) { 
                   
                                ?>
                                <option value="<?php echo $su2["uom_name"]; ?>" <?php if($su2["uom_name"] == $_POST['uom'] ) { echo "selected"; }  ?> ><?php echo $su2["uom_name"]; ?></option>
                                
                                <?php
                                }  
                                ?>
                                </select>
                               
                               </td> 
                               
                             <td><input type="text" required id="price" name="price"   value="<?php echo isset($_POST["price"]) ? $_POST["price"] : ''; ?>" /></td>
                             
              <td><input type="text" readonly id="stock" name="stock" value="<?php echo isset($_POST["stock"]) ? $_POST["stock"] : ''; ?>" /></td>            
                    
                   <td><input type="text"  required id="quantity" name="quantity" value="<?php echo isset($_POST["quantity"]) ? $_POST["quantity"] : ''; ?>" /></td>  
                                                       
</tr>  </table> 

<!-- line item ends--->
 <div class="form-row">
<div class="col-md-4 mb-30">
 <input name="add" class="btn btn-success" type="submit" value="Add" />
</div>
</div>                                            
</form>

form submission

<?php
 if(isset($_POST['add']))
 {
   
   
$customer = $_POST['customer'];
$edate1 = $_POST['edate'];
$edate = date('Y-m-d', strtotime((str_replace('/','-',$edate1))));
	                                            
$pname = $_POST['productname'];
$pcode = $_POST['productcode'];
$uom = $_POST['uom'];
$price = $_POST['price'];
$quantity = $_POST['quantity'];

$pc = mysqli_query($con, "SELECT min_price FROM items WHERE item_id=".$pcode."") or die (mysqli_error($con));
$prow = mysqli_fetch_array($pc);

   // This error part should be displayed inside <div id="error"></div> which is above the form 
if($price<$prow['min_price'])
{
echo  '<div class="alert alert-inv alert-inv-danger alert-wth-icon alert-dismissible fade show" role="alert">
                                        <span class="alert-icon-wrap"><i class="zmdi zmdi-bug"></i></span> Price should not be lesser than minimum price defined.
                                        <button type="button" class="close" data-dismiss="alert" aria-label="Close">
                                            <span aria-hidden="true">×</span>
                                        </button>
                                    </div>';   
}
else
{
  //data gets inserted into invoice table and displays submited data in table format
  // this part should be displayed below the form inside <div id="success"></div>
  
  
}
                        }

Here i am not getting how to define that displays. 

Hello to all,

I have problem figuring out how to properly display data fetched from MySQL database in a HTML table.

In the below example I am using two while loops, where the second one is nested inside first one, that check two different expressions fetching data from tables found in a MySQL database. The second expression compares the two tables IDs and after their match it displays the email of the account holder in each column in the HTML table.

The main problem is that the 'email' row is displayed properly while its while expression is not nested and alone(meaning the other data is omitted or commented out), but either nested or neighbored to the first while loop, it is displayed horizontally and the other data ('validity', 'valid_from', 'valid_to') is not displayed.'

Can someone help me on this, I guess the problem lies in the while loop?
Here is part of the HTML code:

<thead>
 <tr>
 <th data-column-id="id" data-type="numeric">ID</th>
 <th data-column-id="email">Subscriber's Email</th>
 <th data-column-id="validity">Validity</th>
<th data-column-id="valid_from">Valid From</th>
 <th data-column-id="valid_to">Valid To</th>
</tr>
</thead>

Here is part of the PHP code:

    <?php
    while($row = $stmt->fetch(PDO::FETCH_ASSOC))
    {
        echo '
            <tr>
                <td>'.$row["id"].'</td>
        ';
        while ($row1 = $stmt1->fetch(PDO::FETCH_ASSOC)) {
        echo '
                <td>'.$row1["email"].'</td>
        ';
        }
        if($row["validity"] == 1) {
            echo '<td>'.$row["validity"].' month</td>';
        }else{
            echo '<td>'.$row["validity"].' months</td>';
        }
        echo '  <td>'.$row["valid_from"].'</td>
                <td>'.$row["valid_to"].'</td>
        </tr>';
    }
    ?>

P.S. Please know that I have purposely omitted the connection part and the methods in the class that are used in this code to keep the spot of the problem as clean as possible. If you need me to rephrase the question, please ask.

Thank you.