You are correct and that is the future. It is different for every db. The new DAL will have hooks to implement it.
Massimo On Jan 6, 3:14 am, Michael Toomim <too...@gmail.com> wrote: > Here's what I propose: > > In define_table, at this point: > > if migrate: > sql_locker.acquire() > try: > t._create(migrate=migrate, fake_migrate=fake_migrate) > finally: > sql_locker.release() > > At the end, it can read the database schema and see if it contains all > the columns needed in the cPickle .table file. If not, it can output > something like "Sorry, database table %s needs column %s to look like > %s, this needs a manual fix". > > Is this right? I'm not sure how to read a database table schema > programmatically. Is this different for each db? Hopefully it's at > least easy for postgresql. > > On Nov 18 2009, 11:46 am, mdipierro <mdipie...@cs.depaul.edu> wrote: > > > Yes, I would. > > > On Nov 18, 2:03 am,toomim<too...@gmail.com> wrote: > > > > Thanks! Would you accept a patch that makes the error messages more > > > obvious in these situations where you need to manually edit the > > > tables? > > > > I think ROR and Django's approaches to migrations (fully-specifying > > > deltas vs. maintaining static schemas) are both more burdensome than > > > web2py's system of "semi-automatic for most changes (adding columns & > > > tables) but manual for major changes". But the "manual for major > > > changes" part needs better error messages with suggestions for how to > > > proceed. > > > > On Nov 14, 8:04 pm, mdipierro <mdipie...@cs.depaul.edu> wrote: > > > > > You are changing a "text" column (Field) into an "ineteger" column. My > > > > changing the type web2py assumes you want to keep the data and yet it > > > > cannot convert "text" to "integert". You have to do the migration in > > > > two steps: 1) remove the column (comment it and run appadmin) 2) add > > > > the column again with the new type. In this case web2py understands > > > > you do not want to keep the data and will not attempt to do it. > > > > > On Nov 14, 7:08 pm,toomim<too...@gmail.com> wrote: > > > > > > I routinely run into migration problems. I suspect this happens when I > > > > > change a column's datatype, or when I remove a table from db.py and > > > > > then later make a new table with the same name as the old one. > > > > > > In these situations, the migrations get messed up and I get > > > > > stacktraces in sql.py with errors like: > > > > > > ProgrammingError: column "study__tmp" is of type integer but > > > > > expression is of type text > > > > > LINE 1: UPDATE actions SET study__tmp=study; > > > > > ^ > > > > > HINT: You will need to rewrite or cast the expression. > > > > > > How can I migrate in these situations? > > > > > > As an aside, I love the automatic migrations when they work, but I > > > > > don't mind writing sql to fix the underlying database when they don't. > > > > > Could web2py just tell me what schema it expects, let me fix the > > > > > database, and then let me say "OK web2py, the database is ready to > > > > > go!" > >
-- You received this message because you are subscribed to the Google Groups "web2py-users" group. To post to this group, send email to web...@googlegroups.com. To unsubscribe from this group, send email to web2py+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/web2py?hl=en.
