Can't get mysql_affected_rows to confirm delete operation

MySQL database
#1

I am having trouble creating a confirmation that a delete was successful. Here is the code:

$conn = db_connect();
$result = $conn->query(“delete from products where sku=‘1234’”);
if (!$result) {
throw new Exception(‘Error’);
}

The code works perfectly to delete the product, but it never returns an error message if it is unable to delete the product (e.g. if the SKU doesn’t exist).

I found online that I should use mysql_affected_rows so I tried this without success:

$conn = db_connect();
$result = $conn->query(“delete from products where sku=‘1234’”);
if (mysql_affected_rows() == 0) {
throw new Exception(‘Error’);
}

The error I get is:
Warning: mysql_affected_rows() [function.mysql-affected-rows]: Can’t connect to local MySQL server through socket ‘/var/lib/mysql/mysql.sock’ (2) in /home/content/24/10297924/html/secure/user_auth_fns.php on line 188

Out of desperation I also tried mysql_affected_rows($result) and mysql_affected_rows($conn) but I get errors:
mysql_affected_rows() expects parameter 1 to be resource, boolean given…
or
mysql_affected_rows() expects parameter 1 to be resource, object given…

Since I am obviously not understanding how this works I figured someone here surely knows more than me and can help me out.

Thanks very much.

#2

What does this function look like? db_connect()

I’m guessing here (since I can’t see the function) but it looks like mysqli

If that’s the case you would use $conn->affected_rows

#3

Thanks for the reply M@tt. The db_connect() function looks like this:
$result = new mysqli($host, $user, $pass, $database);
if (!$result) {
throw new Exception(‘Could not connect to database server’);
} else {
return $result;
}

Your recommendation did not throw an error, so that is a good sign, but it returned 0 even though the delete took place (so a row was affected and I would have thought it should return 1).

Any thoughts as to why this is? Here is how I call it :

$conn = db_connect();
$result = $conn->query(“delete from products where sku=‘1234’”);
if ($conn->affected_rows == 0) {
throw new Exception(‘Error’);
}

When I simply try to echo ($conn->affected_rows); it returns 0 even when a row is affected.

If you have any idea what is going on thanks for taking the time to let me know.

#4

That should work according to the manual.

http://php.net/manual/en/mysqli.affected-rows.php

#5

Unfortunately it doesn’t. Any thoughts as to why?

#6

You will just need to debug. Are you certain there are no errors and that at least 1 row is being deleted?

[php]
$conn = db_connect();
if ($result = $conn->query(“delete from products where sku=‘1234’”)) {
printf(“Affected rows (UPDATE): %d\n”, $conn->affected_rows);
}
else {
printf(“Error: %s\n”, $conn->error);
}
[/php]

#7

Thanks very much for your help Matt. I played around with it some more and eventually it properly returned the number of affected rows (not sure what the issue was to be honest).

Thanks again for your time.

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