Upgrade from PS 8.1 to 9.0 fails: SQL error when dropping non‑existent index/column

[darkf3d3]

Prerequisites

• I understand and accept the project's code of conduct.
• I have already searched in existing issues and found no previous report of this bug.

Describe the bug and add attachments

When upgrading from PrestaShop 8.x to 9.0 using the autoupgrade module, the upgrade process fails during the database migration step.
The failure occurs because the migration attempts to DROP an index or column (image_type_name) that does not exist in the target database.

This results in a fatal SQL error that stops the upgrade.

Error message
SQLSTATE[42000]: Syntax error or access violation: 1091 Can't DROP 'image_type_name'; check that column/key exists

The error is thrown from:

/classes/db/DbPDO.php line 149
/modules/autoupgrade/.../CoreUpgrader.php

Context
The upgrade log shows that the process reaches the migration file for version 9.0.0, and then fails when executing a query that attempts to drop image_type_name from ps_image_type.
However, in many real‑world installations, this index/column may have already been removed.

Expected behavior

Prestashop upgrade module should
Check whether the index or column exists before attempting to drop it
or use DROP INDEX IF EXISTS / DROP COLUMN IF EXISTS (MySQL 8+)
or wrap the operation in a conditional query using information_schema

Steps to reproduce

From a PrestaShop 8.x installation where the table ps_image_type does not contain the index/column image_type_name.
Launch the upgrade to PrestaShop 9.0 using the autoupgrade module.
The upgrade stops during the SQL migration step with error 1091.

PrestaShop version

8.1

[darkf3d3]

After further investigation, the failing query is not attempting to drop the column, but the index named image_type_name.
The problematic line is located in:
modules/autoupgrade/upgrade/sql/9.0.0.sql
and contains:
ALTER TABLE PREFIX_image_typeCHANGEid_image_type id_image_typeint(10) unsigned NOT NULL AUTO_INCREMENT, CHANGEwidth widthint(10) unsigned NOT NULL, CHANGEheight heightint(10) unsigned NOT NULL, CHANGEproducts products tinyint(1) NOT NULL DEFAULT '1', CHANGEmanufacturers manufacturers tinyint(1) NOT NULL DEFAULT '1', CHANGEstores storestinyint(1) NOT NULL DEFAULT '1', DROP keyimage_type_name, ADD UNIQUE KEY UNIQ_907C95215E237E06 (name);

This index does not exist in any real PrestaShop 8.x installation.

[Hlavtox]

@Quetzacoalt91 @darkf3d3 I think that a drop_index_if_exists.php helper simmilar to drop_column_if_exists.php must be introduced.

(MySQL doesn't support DROP INDEX IF EXISTS.)

[Quetzacoalt91]

Yes, implementing this method should be difficult as we already have similar methods (add_index_if_not_exists), but note it hides an unexpected change on the store

This index does not exist in any real PrestaShop 8.x installation.

It does actually: https://github.com/PrestaShop/PrestaShop/blame/95e699fe6e5e015c333094537c369992fc210597/install-dev/data/db_structure.sql#L1053

And the index was found on PS 1.6 and probably even earlier.
PrestaShop/PrestaShop@fcab98b#diff-e98d435095567c145b49744715fd575eaab7050328c211b33aa9a37158421ff4R943

Either a module or someone changed the structure of the database, you can recreate the index before trying again.
Even if we plan to add a safety net in Update Assistant, this specific error is not caused by the module itself. So this issue can be closed.

[darkf3d3]

Personally I haven't modified the database, but over the years I've updated PS version several times and obviously used different modules.
However, regardless of this, I believe it's useful to eliminate any possible cause of update failure, especially considering that if the update fails the site breaks and you have to resort to restoring a backup.

[AureRita]

Hi @darkf3d3 ,

Thank you for your report, I reproduce the issue with PrestaShop version 8.2.x, as you can see :

Capture.video.du.2026-02-03.15-11-57.mp4

I'll add this to the backlog so it can be fixed.

Please be aware that some issues might take a very long time to be resolved.

If you fix the issue on your end, please contribute it back to the project. Remember that the more people contribute, the better PrestaShop becomes for everyone.

Moreover, Autoupgrade have now is own issue center ! So I'll transfer your issue in the good repository

Thanks