Comparing floats for equality is an issue with MySQL. Floats are rarely equal, since the internal representation can be different than the actual number. You'd want to use a different data type, or make your comparison a greater than or less than.
On Wednesday, May 1, 2013 6:59:27 AM UTC-7, AnnG wrote: > > Hi, > > I have a DAL query which works OK when selecting integer 'float' fields > (eg 4.0, 5.0, 6.0) (I'm using a MySQL database), but does not select rows > containing actual float numbers (eg 6.3). > > Here is the code > > for table_row in db((db.field_phenotype.field_phenotype_pk == db. > scaninstance_fieldphenotype.field_phenotype_fk) & (db. > scaninstance_fieldphenotype.scaninstance_fk == db.scaninstance. > scaninstance_pk) & (db.scaninstance.patient_fk == self.patient_id) > > & (db.scaninstance.age_months == age_months) ##### goes wrong here > > ).select(db.field_phenotype.name, db.scaninstance_fieldphenotype. > field_phenotype_value): > ... > > ... The 'age_months' variable is copied from an earlier query from the > same table/field. That earlier query works fine, returning all floats - > which print out fine on my web-page. > The query shown above only matches with rows where the > db.scaninstance.age_months > is an integer (converted to a float) eg 4.0, 5.0, 64.0 > but not for actual floats eg 6.3 > > Can anyone help?? > > Regards > > Ann > -- --- 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 web2py+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
