how to sum table1 and table2 (simple sum) - php

Question

How I can sum Table1 and Table2
If table1 have more than one entry status "0" and table2 also more than one entry status "0" then sum Table1 + Table2.
Example
Table1 have 3 entrys with status "0" and table2 have 2 entrys with status "0" then sum is 2
Like first table = 1 and second table = 1
And if table1 have entries and table2 doesnt have entries then sum is 1
and if Both doesnt have entries then sum is 0
I tryed this if statements:
require_once('../../function.php');
try{
$database = new Connection();
$db = $database->openConnection();
$status = 0;
$sql = "SELECT ( SELECT COUNT(*) FROM contact WHERE status = 0 ) AS contact, COUNT(*) AS ordr FROM orrdr WHERE status = :status";
$qry = $db->prepare($sql);
$qry -> bindParam(':status', $status, PDO::PARAM_INT);
$qry -> execute();
$count = $qry->fetchColumn();
} catch (PDOException $e) {
echo "There is some problem in connection: " . $e->getMessage();
}
if ($count['contact'] => 1 && $count['ordr'] => 1) {
echo "2";
} elseif (empty($count['contact']) && empty($count['ordr']) {
echo "0";
} elseif () {
# code...
}
This is counting for notifications.
Status 1 is readed notification and status 0 is not readed notification.
I didnt finish my statements because I know this is wrong way to do it.

Answer 1

You can use the following SQL:
SELECT SUM(x.cnt)
FROM (
SELECT IF(COUNT(*) > 0, 1, 0) AS cnt FROM contact WHERE status = 0
UNION ALL
SELECT IF(COUNT(*) > 0, 1, 0) FROM orrdr WHERE status = 0
)x
So you can use the following PHP code:
require_once('../../function.php');
try {
$database = new Connection();
$db = $database->openConnection();
$status = 0;
$sql = "SELECT SUM(x.cnt) FROM (SELECT IF(COUNT(*) > 0, 1, 0) AS cnt FROM contact WHERE status = :status UNION ALL SELECT IF(COUNT(*) > 0, 1, 0) FROM orrdr WHERE status = :status)x";
$qry = $db->prepare($sql);
$qry -> bindParam(':status', $status, PDO::PARAM_INT);
$qry -> execute();
$count = $qry->fetchColumn();
} catch (PDOException $e) {
echo "There is some problem in connection: " . $e->getMessage();
}
echo $count;
If you need to know the sums of both queries you can use the following:
require_once('../../function.php');
try {
$database = new Connection();
$db = $database->openConnection();
$status = 0;
$sql = "SELECT (SELECT COUNT(*) FROM contact WHERE status = :status) AS cnt_contact, (SELECT COUNT(*) FROM orrdr WHERE status = :status) AS cnt_orrdr";
$qry = $db->prepare($sql);
$qry -> bindParam(':status', $status, PDO::PARAM_INT);
$qry -> execute();
$count_contact = $qry->fetchColumn(0);
$count_orrdr = $qry->fetchColumn(1);
} catch (PDOException $e) {
echo "There is some problem in connection: " . $e->getMessage();
}
if ($cnt_contact >= 1 && $cnt_orrdr >= 1) {
echo "2"; //both available.
} elseif($cnt_contact >= 1 && $cnt_orrdr == 0) {
echo "1"; //only contact available.
} elseif ($cnt_orrdr >= 1 && $cnt_contact == 0) {
echo "1"; //only orrdr available.
} elseif ($cnt_orrdr == 0 && $cnt_contact == 0) (
echo "0"; //nothing available.
}
//simpler solution instead of "if" above:
//echo (($cnt_contact > 0 ? 1 : 0) + ($cnt_orrdr > 0 ? 1 : 0));