// sql to insert a record
$sql1 = "INSERT INTO student (student_id, student_gen, student_fname) VALUES ('John', 'Doe', 'john@example.com')";
$result1 = $link->query($sql1);
// sql to update a record
$sql = "UPDATE student SET student_fname='Doe' WHERE student_id=2";
$result1 = $link->query($sql1);
// sql to delete a record
$sql = "DELETE FROM student WHERE student_id=3";
$result1 = $link->query($sql1);