Question

My mysql query is working fine

INSERT INTO donor_location (pc_id)
SELECT id
FROM pc
WHERE postcode= ?

i.e gets the postcode id from a postcode table then inserts that id into donor_location table.
I am using mysqli and prepared statements

without the select part it would be quite easy – something like

$stmt = $mysqli->prepare("INSERT INTO donor_charity(
id) values (?)") ;

however I am completely lost about how to incorporate the select

Answer 1

You need to use Bind_param after Prepare statement.

$sql = "INSERT INTO donor_charity(
id) values (?)
       ";
/* create a prepared statement */
if (!$stmt = $db->prepare($sql)) {
    echo 'Database prepare error';
    exit;
}

 /* bind parameters for markers */
$stmt->bind_param('ssssss', $id);

$id = '123456';

 /* execute query */
$stmt->execute();