Unable to use backoffice SQL Manager, getting error "Db::getArrray method can be used for SELECT queries only."

[papagino]

Hello people, today, I tried to use SQL Manager in the Backoffice to do an SQL query for an email campaign, but as soon as I click to view the results,  I get this error : "Db::getArrray method can be used for SELECT queries only."

If I try to export the query instead,  I get a "This site can’t be reached" page with this error:

The webpage at https://www.xxxxxxxxxxxxxxx/index.php?controller=AdminRequestSql&token=xxxxxxxxxxxxxxxxxxxxxxxxxx&id_request_sql=2&exportrequest_sql=1 might be temporarily down or it may have moved permanently to a new web address.
ERR_INVALID_RESPONSE

Errors logs shows this:

Stacktrace

#0 controllers/admin/AdminRequestSqlController.php(511)
#1 classes/db/Db.php(1100): ()
#2 controllers/admin/AdminRequestSqlController.php(511): DbCore->getArray()
#3 controllers/admin/AdminRequestSqlController.php(343): AdminRequestSqlControllerCore->generateExport()
#4 classes/controller/Controller.php(209): AdminRequestSqlControllerCore->initContent()
#5 classes/Dispatcher.php(858): ControllerCore->run()
#6 admin123/index.php(58): DispatcherCore->dispatch()

I'm on Thirtybees 1.6.0

Any idea why I get this error?

Any help would be appreciated

Cheers,

Edited 1 hour ago by papagino

[the.rampage.rado]

The SQL manager is heavily restricted in the operations it can do to limit exposure of the DB to bad actors.

Give us the query you want to run so we can check for a better version.

[papagino]

14 minutes ago, the.rampage.rado said:

The SQL manager is heavily restricted in the operations it can do to limit exposure of the DB to bad actors.

Give us the query you want to run so we can check for a better version.

... not sure what you mean with " for a better version." but I basically need these queries:  

id_customer, id_shop_group, id_lang, firstname, lastname, email, newsletter, date_add