如何找到sql结果数组的差异

Question

I am using PHP and SQL Server for my web application project. I have two sets of queries with objective find differences between them.

Below is draft code in my mind for you to review.

    $sql_a = new sqlsrv();
    $sql_a->query("SELECT a, b FROM db_a WHERE dday=1 and dmth=2 and dyr=2015 and b>'0'");

    $sql_b = new sqlsrv();
    $sql_b->query("SELECT ax, sum(bx) FROM db_b WHERE dday=1 and dmth=2 and dyr=2015 GROUP BY ax");

while (($sql_ar = $sql_a->fetch()) and ($sql_br = $sql_b->fetch())) {
print_r(array_diff($sql_br,$sql_ar);
}