For some reason, the above code actually gets the values from the database, despite there not being a mysqli_query() in sight
This of course is quite impossible, unless you are getting something from a previously executed query that uses the same variable names.
I think your main problem is that accessing the value of the query coded using just SELECT MAX(employee_id)
will return a column with the name MAX(employee_id)
and that is not a valid PHP variable name. So what you have to do is give that column another name that is a valid PHP variables name using this syntax SELECT MAX(employee_id) as max_empid
which renames the column to max_empid
I am assuming nothing so I will also include a connection to the database in my answer. You will need to replace the my_user
, my_password
and my_db
values, or ignore the connection if you have already dont that somewhere else. I have also used the Object Oriented approach to MYSQLI, if you are using the proceedural calls, you may have to amend the code accordingly
// connect to your database
$mysqli = new mysqli('localhost', 'my_user', 'my_password', 'my_db');
// build query and use an alias for the `MAX(employee_id)`
// so you can easily use its name in the result set
$sql = "SELECT MAX(employee_id) as max_empid FROM employees";
// Now we must execute this query
$result = $mysqli->query($sql);
// Now we must chech that the query worked
if ( $result === FALSE ) {
echo sprintf( 'Query Failed: %s<br>%s', $sql, $mysqli->error);
exit;
}
// now we must read one of the rows from the result set
// produced by the ->query() command.
// In this case there of course there is only one result row
$row = $result->fetch_object();
echo 'Id: ' . $row->max_empid;