Using radio buttons to get data from PHP query - php

Question

I have a random chat feature which allows users to randomly pair against another based on the parameters set by the user. The parameters are age (min: 17, max: 50) and gender (can chat with male, female, or any which means no preference).
When submit is clicked, it is easy to set queries if the radio values are male or female, because those are the values I am storing in my database, but I am unsure on how I can pair someone with another if the value is any.
Here are the radio buttons:
<input type="radio" name="gender" value="male">Male</input> <br />
<input type="radio" name="gender" value="female">Female</input><br />
<input type="radio" name="gender" value="any">Any</input>
<input type="submit" class="btn btn-info" name="submit" value="Click to start chat! " />
P.s. The radio buttons are in a form but have no action.
<form action="#" method="POST" enctype="multipart/form-data">
And here is my approach so far:
<?php
$age_from = #$_POST['age_from'];
$age_to = #$_POST['age_to'];
$gender = strip_tags(#$_POST['gender']);
if (isset ($_POST ['submit'])){
// Chat with parameters script
$any_chat = mysqli_query($connect, "SELECT * FROM users WHERE age BETWEEN '$age_from' AND '$age_to' AND gender = '$gender'
ORDER BY RAND() LIMIT 1");
$num_of_rows = mysqli_num_rows ($any_chat);
while ($get_any_rand_user = mysqli_fetch_assoc($any_chat)){
$rand_name = $get_any_rand_user['username'];
$acc_type = $get_any_rand_user['account_type'];
if ($acc_type != "admin" ){
if ($rand_name == $username){
$any_chat;
} else{
header ("Location: /messages.php?u=$rand_name");
}
}
if ($num_of_rows == 0){
echo "No results found. Try changing your query.";
}
} // while closed
}
?>
As you can see in the query gender = '$gender' can only retrieve a row if the gender is male or female (because they are the values in the db). But if any is selected, $gender will equal any which is not valid, since their is no user in my system with gender of any.
How can I work my way around this?

Answer 1

I would do something like this. Create a variable to store your query and only add the gender condition if $gender is male or female.
<?php
$age_from = #$_POST['age_from'];
$age_to = #$_POST['age_to'];
$gender = strip_tags(#$_POST['gender']);
if (isset ($_POST ['submit'])){
// Chat with parameters script
$sql = "
SELECT *
FROM users
WHERE age BETWEEN '$age_from' AND '$age_to'
";
if (!empty($gender) && ($gender == 'male' || $gender == 'female')) {
$sql .= " AND gender = '$gender' ";
}
$sql .= " ORDER BY RAND() LIMIT 1 ";
$any_chat = mysqli_query($connect, $sql);
$num_of_rows = mysqli_num_rows ($any_chat);
while ($get_any_rand_user = mysqli_fetch_assoc($any_chat)){
$rand_name = $get_any_rand_user['username'];
$acc_type = $get_any_rand_user['account_type'];
if ($acc_type != "admin" ){
if ($rand_name == $username){
$any_chat;
} else{
header ("Location: /messages.php?u=$rand_name");
}
}
if ($num_of_rows == 0){
echo "No results found. Try changing your query.";
}
} // while closed
}
?>

Answer 2

if (isset ($_POST ['submit'])){
// Chat with parameters script
$sql_builder = "SELECT * FROM users WHERE age BETWEEN '$age_from' AND '$age_to'";
if($gender != 'any'){
$sql_builder .= "AND gender = $gender";
}
$sql_builder .= "ORDER BY RAND() LIMIT 1";
$any_chat = mysqli_query($connect, $sql_builder);