Trouble with mySQL query. Need * instead of ' * ' - php

Question

I have the following code that doesn't work. It doesn't work because it will do a query
WHERE column = ' * ', instead of WHERE column = *
I tried to think of a way to get it so it will do WHERE variable = 'var' if a variable is posted in the form and WHERE column = * if not posted, but I can't think of a way, and everything I tried is hacky or not working.
if(isset($_POST['variable'])){
$variable=$_POST['variable'];
}
else{$variable='*';}
$sql="SELECT * FROM table WHERE column = '$variable'";
EDIT, Here is the actual code:
<form method='post' action='policy.php?go'>
<input type='radio' name='gen' value='M'>Male
<input type='radio' name='gen' value='F'>Female
<select name='state'>
<option value='AK'>AK</option>
<option value='WY'>WY</option>
</select>
<input type='radio' name='logic' value='>'>Older Than
<input type='radio' name='logic' value='<'>Younger Than
<select name='age'>
<option value='5'>5</option>
<option value='11'>11</option>
<option value='17'>17</option>
<option value='65'>65</option>
</select>
<input type='submit' name='submit' value='Search'>
</form>
<?php
if(isset($_GET['go']) && isset($_POST['submit'])){
if(isset($_POST['state'])){
$state="'".mysql_real_escape_string( $_POST['state'] )."'";
}
else{ $state='*';}
if(isset($_POST['age'])){
$age=$_POST['age'];
//append to query string
}
if(isset($_POST['logic'])){
$log=$_POST['logic'];
//append to query string
}
else{$log='';}
if(isset($_POST['gen'])){
$gen="'".mysql_real_escape_string( $_POST['gen'] )."'";
}
else {$gen='*';}
echo "<table id='hor-minimalist-b' summary='Employee Pay Sheet' class='tablesorter'>
<caption>Age: ".$log." ".$age." Gender: ".$gen." </caption>
<thead>
<tr>
<th scope='col'>State</th>
<th scope='col'>Number</th>
</tr>
</thead>
<tbody>";
// (WHY IS THIS NOT WORKING?)
$sql = "SELECT SUM(num) AS sum, state,gen,age FROM `policy-ssi`
WHERE age $log $age AND gen = $gen
GROUP BY state
ORDER BY sum DESC";
$result = mysql_query($sql);
while ($row = mysql_fetch_assoc($result)) {

Answer 1

In MySQL, the wildcard character for strings is % rather than *. In order to match the field regardless of what's in it, change else {$gen='*';} to else {$gen='\"%\"';}
Also, in order to use the wildcard, your query should become
$sql = "SELECT SUM(num) AS sum, state,gen,age FROM `policy-ssi`
WHERE age $log $age AND gen LIKE $gen
GROUP BY state
ORDER BY sum DESC";