How do I format the links from a mysql query to show click here on my webpage.

$row (eg of reviewlink =

I want this result to show in the html source code:

<a href="" >click here</a>

So the page shows click here and links to

I want the click here to show inside a table cell.

This does not work!
echo "<td>" . "<a href=$row>click here</a>" . "</td>";

This works but just shows the unclickable url
echo "<td>" . $row . "</td>";

What is the php echo statement that I have to use for this to work?