[5.x]: Error: Undefined constant PDO::MYSQL_ATTR_MULTI_STATEMENTS in vendor/craftcms/cms/src/helpers/App.php:1051

[urbantrout]

What happened?

Upgraded from 5.9.12 to 5.9.13 and I got a server error:

Error: Undefined constant PDO::MYSQL_ATTR_MULTI_STATEMENTS in /var/www/project/cms/vendor/craftcms/cms/src/helpers/App.php:1051

PHP version 	8.4.15
OS version 	Linux 6.17.8-orbstack-00308-g8f9c941121b1
Database driver & version 	PostgreSQL 16.10
Image driver & version 	Imagick 3.8.1 (ImageMagick 7.1.1-41)
Craft edition & version 	Craft Pro 5.9.13
Yii version 	2.0.54
Twig version 	v3.21.1
Guzzle version 	7.10.0

PDO
PDO support 	enabled
PDO drivers 	sqlite, pgsql
pdo_pgsql
PDO Driver for PostgreSQL 	enabled
PostgreSQL(libpq) Version 	17.7

Craft CMS version

5.9.13

PHP version

8.4.15

Operating system and version

Linux 6.17.8-orbstack-00308-g8f9c941121b1

Database type and version

PostgreSQL 16.10

Image driver and version

Imagick 3.8.1 (ImageMagick 7.1.1-41)

Installed plugins and versions

[linear]

CMS-1855

[ingolfurs]

We are also experiencing this issue after upgrading from 5.9.12 to 5.9.13 on our projects.
It's a critical blocker preventing us from deploying 5.9.13 to production.

[PromontoryProtean]

My company is running into this as well when updating to 4.17.7. We host in Azure and this setting has broken our DB connections. Luckily we caught this in staging before deploying to production. We were in the process of patching numerous sites against a critical vulnerability in the Azure blob storage plugin, so this is a critical blocker for us as well. Need guidance ASAP on whether to wait for a patch vs making a change to the DB config in our base containers. For us the error is:

Exception 'craft\errors\DbConnectException' with message 'Craft CMS can’t connect to the database.'

in /app/vendor/craftcms/cms/src/db/Connection.php:200

Caused by: Exception 'yii\db\Exception' with message 'SQLSTATE[HY000] [3159] Connections using insecure transport are prohibited while --require_secure_transport=ON.'

in /app/vendor/yiisoft/yii2/db/Connection.php:652

Error Info:
Array
(
    [0] => HY000
    [1] => 3159
    [2] => Connections using insecure transport are prohibited while --require_secure_transport=ON.
)

Caused by: Exception 'PDOException' with message 'SQLSTATE[HY000] [3159] Connections using insecure transport are prohibited while --require_secure_transport=ON.'

in /app/vendor/yiisoft/yii2/db/Connection.php:726

[urbantrout]

Apparently this is the culprit:

PDO::MYSQL_ATTR_MULTI_STATEMENTS is provided by the pdo_mysql extension when built with the mysqlnd client library; if pdo_mysql is missing or built against libmysqlclient, the constant may not exist.

[johnnynotsolucky]

@urbantrout, it looks like you're using pgsql and don't have pdo_mysql extension enabled. The recent change seems to add that constant to the db config for all drivers, not just MySQL. Perhaps it should be configured only for MySQL drivers?

[urbantrout]

Yeah, that makes sense! #18476 only checks for the constant regardless of the db driver

[PromontoryProtean]

We use MySQL in our environment with a db.php to set the Azure certificate, and our connections are now broken. I guess this is conflicting with the recent changes somehow?

<?php

use craft\helpers\App;

return [
    'attributes' => [
        PDO::MYSQL_ATTR_SSL_CA => CRAFT_BASE_PATH . '/mysql/AzureMySQL.pem'
    ],
];

[coffeedave]

We also use Azure MySQL and we're seeing the same issue with connections failing to connect to the database. Rolling back to 5.9.12 fixes the issue. I've tried compiling pdo_mysql with mysqlnd and it doesn't resolve the issue for us.
We have additional MYSQL env parameters for SSL encryption that are not being picked up by craft. I can replicate the same on a local MySQL database in docker with SSL enabled, so it's a more general issue than Just Azure SQL.

[brandonkelly]

Thanks all, and sorry about this. Fixed for the next release, which should go out soon.