I agree that is the problem:
Field("description", "string", length=2048),
according to: http://dev.mysql.com/doc/refman/5.0/en/char.html
"Values in VARCHAR columns are variable-length strings. The length can
be specified as a value from 0 to 255 before MySQL 5.0.3, and 0 to
65,535 in 5.0.3 and later versions".
We set varchar max to 255 to avoid problems with older versions of
mysql. Since problems were reported by users.
There should not have been a migration in your case. I will look in
this more.
On Jan 22, 2:43 pm, "Jonathan Z." <jzem...@gmail.com> wrote:
> It's probably also important to note that the "before" table existed
> since 1.85.x. I keep the "migrate=False" flag set on it, until I make
> a change. As I noted previously, the change happened on 1.91.6. So
> the issue is data loss affected by changes in the web2py DAL.
>
> I've been digging around, and my guess is that this line (3694) in
> dal.Table is the problem:
>
> field.length = min(field.length,self._db and
> self._db._adapter.maxcharlength or INFINITY)
>
> Since maxcharlength for MySQLAdapter is 255, this has the affect of
> silently truncating my specified field lengths.
>
> On Jan 22, 11:48 am, "Jonathan Z." <jzem...@gmail.com> wrote:
>
>
>
>
>
>
>
> > Massimo,
>
> > Here is an example of one of the tables that got a truncated field:
>
> > before...
>
> > db.define_table("thing",
> > Field("user_id", db.auth_user, notnull=True, readable=False,
> > writable=False),
> > Field("title", "string", length=128, notnull=True, unique=True,
> > required=True),
> > Field("slug", "string", length=128, notnull=True, unique=True,
> > required=True),
> > Field("state", "string", length=10, notnull=True, required=True,
> > default="created", requires=IS_IN_SET(("created", "started",
> > "completed"))),
> > Field("description", "string", length=2048),
> > Field("created", "datetime", notnull=True, readable=False,
> > writable=False, default=request.now),
> > Field("updated", "datetime", readable=False, writable=False,
> > update=request.now),
> > Field("uuid", "string", length=16, notnull=True, unique=True,
> > readable=False, writable=False),
> > format="%(title)s"
> > )
>
> > after...
>
> > db.define_table("thing",
> > Field("user_id", db.auth_user, notnull=True, readable=False,
> > writable=False),
> > Field("title", "string", length=128, notnull=True, unique=True,
> > required=True),
> > Field("slug", "string", length=128, notnull=True, unique=True,
> > required=True),
> > Field("state", "string", length=10, notnull=True, required=True,
> > default="created", requires=IS_IN_SET(("created", "started",
> > "completed"))),
> > Field("description", "string", length=2048),
> > Field("things", "list:string"), # NEW FIELD
> > Field("created", "datetime", notnull=True, readable=False,
> > writable=False, default=request.now),
> > Field("updated", "datetime", readable=False, writable=False,
> > update=request.now),
> > Field("uuid", "string", length=16, notnull=True, unique=True,
> > readable=False, writable=False),
> > format="%(title)s"
> > )
>
> > After this change (addition of a new field) and subsequent DB
> > migration, the "description" field was truncated from 2048 characters
> > to 255. Note that this change didn't alter the field length on
> > sqlite. But it did truncate the description field on mysql.
>
> > On Jan 22, 10:55 am, Massimo Di Pierro <massimo.dipie...@gmail.com>
> > wrote:
>
> > > Can you tell us what the model was before and after migration?
>
> > > Massimo
>
> > > On Jan 22, 10:02 am, "Jonathan Z." <jzem...@gmail.com> wrote:
>
> > > > I have a number of fields specifying a length > 255 (some as large as
> > > > 2K). On a recent schema migrate, web2py truncated all of these fields
> > > > to 255, resulting in substantial data loss.
>
> > > > My database is mysql. I'm on version 1.91.6 of web2py. I'm pretty
> > > > sure this has something to do with the new DAL.
