Did you change the MySQL connection string? By default, the names of the *.table files are prefixed with a hash of the connection string, so if you change the connection string, the hash will change, and none of the existing *.table files will be recognized. For a simple fix, you can force the DAL to recognize the original hash -- just grab the prefix from an existing *.table file and do:
db = DAL(..., table_hash=[the original connection string hash]) Anthony On Friday, December 15, 2017 at 6:26:05 PM UTC-5, SimonD wrote: > > > I've just upgraded from 2.14.6 to 2.16.1, and for the first time ever > since using web2py (in years), I encountered a "(1050, "Table 'xxxxx' > already exists")" error. > I applied "db = DAL(...,migrate=False)" and this worked OK. If I remove > the migrate=False I see the error again. > I upgraded on a local server using 2.16.1 and a copy of the apps' folder > and a restored mysqldump from my VPS running 2.14.6. This is my usual > upgrade/test method. > > I'm a little perplexed why I see the error, because the app's entire > folder and the mysql have not changed. Only the web2py version has changed > (and I am using a different mysql host with the same data). I've not seen > this when upgrading in the past. > I also wish to enable migrations but the error re-occurs if I do. > > Although the fix is documented and database migration is explained in the > book, I have not been able to find information about what migrate= does > 'under the hood'. Same for fake_migration. Hence I am unsure what strategy > to adopt to properly fix the snag. > > 1) Why do I see the above error when simply up-versioning web2py? The > mysql DB and app's models have not changed. Nor is there any change > anywhere in the app's entire folder. > 2) I have read notes about .table files, but I thought these were used > only for sqlite. Do these play a role in mysql also? > 3) I am also unclear of exactly what fake-migration really do i.e. "db = > DAL(...,fake_migrate_all=True)". I want to restore migration=true - is a > fake_migration the way to fix whatever problem is causing the error? And > what does it actually do? > > > I'm sorry for these basic questions. I have a poor understanding of what > the migrate and fake_migrate arguments really do, how they work, and what > they check to trigger the above error. Google is usually my friend, but not > in this case. > I am sure a better 'under the hood' understanding would help me. Is there > a great explanation somewhere, please, that will help me to get set > migrate=True without further errors? > > Many thanks > > -- Resources: - http://web2py.com - http://web2py.com/book (Documentation) - http://github.com/web2py/web2py (Source code) - https://code.google.com/p/web2py/issues/list (Report Issues) --- You received this message because you are subscribed to the Google Groups "web2py-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
