Select all records when no value is supplied - php

Question

I have a function in php that does retrieval and display work from a MySql database.
It's like this:
function thisFunction($id,$country,$year){
global $conn;
$conn = connect();
$stmt = $conn->prepare("select * from table where id = :id and countryCode = :country and YEAR(addedDate) = :year and status = 0");
$stmt->execute(array(
':id' => $id,
':country' => $location,
':year' => $year
));
}
The problem is, sometimes $id has a value, sometimes it doesn't. When it does have a value, I'd like to select records with that value, when it doesn't I'd like to select all.
How do I write the sql in there, or do this thing, so that when there is a value it'll select only records with that value, and when there isn't a value, it'll select all. It's the part where when no value is selected - then select all where I'm stuck.
I call the function like anyone would. Nothing unique there.
select * from table where id = 9 -- works fine - displays all records where id = 9
select * from table where id = no value supplies - should display all value. How do I do this?
Can you please help?
select * from table where id = * //Does not work

Answer 1

Just remove the id part if it's empty:
function thisFunction($id,$country,$year){
global $conn;
$conn = connect();
if (!isset($id) || empty($id))
{
$stmt = $conn->prepare("select * from table where countryCode = :country and YEAR(addedDate) = :year and status = 0");
$stmt->execute(array(
':country' => $location,
':year' => $year
));
}
else
{
$stmt = $conn->prepare("select * from table where id = :id and countryCode = :country and YEAR(addedDate) = :year and status = 0");
$stmt->execute(array(
':id' => $id,
':country' => $location,
':year' => $year
));
}
}

Answer 2

select * from table where id = id;
Sample fiddle

Answer 3

You could use something like this:
function thisFunction($id,$country,$year){
global $conn;
$sql_query = "select * from table where status = 0";
$where_data = array();
if(isset($id) && $id != '*'){ // Only add this if ID is set to something other than *
$where_data[':id'] = $id;
$sql_query .= " AND id = :id";
}
if(isset($location)){
$where_data[':country'] = $location;
$sql_query .= " AND countryCode = :country";
}
if(isset($year)){
$where_data[':year'] = $year;
$sql_query .= " AND YEAR(addedDate) = :year";
}
$conn = connect();
$stmt = $conn->prepare($sql_query);
$stmt->execute($where_data);
}

Answer 4

you could potentially select them if the column is not null.
select * from table where id is not null