I'm new to Drupal and it's pretty much my first experience of adding Modules. I've mostly being using the Migrate module so far in.

On loading I'm getting PDO errors which are created by either missing tables not being added or missing fields in the database. This also happens when I set up my own migrate extension - in regards to the mapping.

PDOException: SQLSTATE[42S02]: Base table or view not found: 1146 Table 'r.migrate_group' doesn't exist: SELECT mg.name AS name, mg.title AS title, mg.arguments AS arguments FROM {migrate_group} mg; Array ( ) in migrate_ui_migrate_dashboard() (line 29 of /sites/all/modules/contrib/migrate/migrate_ui/migrate_ui.pages.inc).

I can fix these errors - at least to the point of being able to have access to the Migrate UI . By looking in the migrate.install file

ALTER TABLE `migrate_status` ADD `group_name` VARCHAR( 255 ) NOT NULL COMMENT 'name of group' AFTER `machine_name`

This is not the only table I'm having to fix; but an example.

Also I think it's worthy of noting that the tables I'm fixing have commands such as 'serialize' On another test website I am now receiving a similar PDO error.

So my question is why this is happening and a permanent fix for when I reinstall this or any other modules

I have Drupal Commons 7x-3.12 core installed using Acquia .

Mysql version SELECT @@version;

Thank you for any advice that will push me in the right direction as to why I'm getting this issue.

1 Answer 1


I noticed that I was getting this error only on Modules that I've been installing directly into the modules/contrib/ folder. Using the 'Install new module' button in 'Modules' installation was not bringing up the PDO exception.

By the way if anyone else couldn't find that button thats becuase you need to activate the 'Update Manager' module first to be able to see it.

I hope this helps anyone else search for the same issue.

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