When you update a module, but there's an unhandled error, then you can't do anything because the queue of modules to install still tries to install the module, so unless you correct the error you can't do anything in the database.
I remember reading an answer, maybe in this site, in which one person had a problem updating a module, and an answerer gave him a sql command to manually cancel the update of the module in the meantime. I think it was a table that had a field that indicated that the module was to be updated.
I can't for the life of me find this command again nor I haven't been able to find by searching the schema the table and field which did the trick. Anyone knows it?