Edit report at https://bugs.php.net/bug.php?id=69884&edit=1
ID: 69884
Comment by: call dot user dot func at gmail dot com
Reported by: phpbugs at olemartin dot org
Summary: mysqli->connect_error seems to be shared across
objects
Status: Verified
Type: Documentation Problem
Package: MySQLi related
Operating System: Ubuntu
PHP Version: 5.5.26
Block user comment: N
Private report: N
New Comment:
Hi, this behaviour is the same in php8+. A warning in the docs would've been really helpful, as
it's a pain to debug.
A very brief testcase:
$db1 = new MySQLi("localhost", "root", "", "mysql", 3306);
var_dump("1: ".$db1->connect_error); // not error, db exist
$db2 = new MySQLi("localhost", "root", "",
"some_non_existing_db", 3306);
var_dump("2: ".$db2->connect_error); // error, db not exist
// db2 shared error to db1 which is wrong, db1 is still valid
var_dump("3: ".$db1->connect_error); // not error, db exist
Previous Comments:
------------------------------------------------------------------------
[2018-08-14 02:54:13] requinix@php.net
The values are indeed "shared", meaning the values are not associated with a specific
instance but set globally.
------------------------------------------------------------------------
[2018-08-13 21:14:30] brak at gameservers dot com
I'm also seeing this same behavior on PHP 7.1.19 running on CentOS 7
------------------------------------------------------------------------
[2015-06-19 14:19:44] phpbugs at olemartin dot org
Description:
------------
It seems that the \mysqli->connect_error and \mysqli->connect_errno values (when using mysqli
in the object-oriented mode) shares state between all connections. This is not documented (it should
at least have a warning in the documentation).
When running the example code (make sure you point the first and last connection to a valid MySQL
server) i found that all connections reported no errors, although the second one failed. Sometimes
(although I'm having a hard time reliably reproducing this) i'm pretty sure i've also
seen all three connections report errors (although the third and last connection succeeded). Maybe
this value is not overwritten when a successful connection is done, in all code paths?
Either way, i think this should be either documented or fixed - as one would not expect this
information to be shared between instances when the syntax doesn't indicate that. If this is a
static property, i would expect the documentation said to use \mysqli::$connect_error, but that
doesn't even work.
Test script:
---------------
$connections = array(
'Valid connection' => new mysqli('127.0.0.1', 'root',
'', 'test', 3306),
'Invalid connection' => @new mysqli('127.0.0.1', 'root',
'', 'test', 3307),
'Valid connection 2' => new mysqli('127.0.0.1', 'root',
'', 'test', 3306),
);
foreach($connections as $desc => $conn) {
echo "$desc:\n".
"connect_error = ".$conn->connect_error."\n".
"connect_errno = ".$conn->connect_errno."\n".
"ping = ".@$conn->ping()."\n\n".
}
Expected result:
----------------
Valid connection:
connect_error =
connect_errno = 0
ping = 1
Invalid connection:
connect_error = Connection refused
connect_errno = 2002
ping =
Valid connection 2:
connect_error =
connect_errno = 0
ping = 1
Actual result:
--------------
Valid connection:
connect_error =
connect_errno = 0
ping = 1
Invalid connection:
connect_error =
connect_errno = 0
ping =
Valid connection 2:
connect_error =
connect_errno = 0
ping = 1
------------------------------------------------------------------------
--
Edit this bug report at https://bugs.php.net/bug.php?id=69884&edit=1