On Jul 27, 2011, at 8:56 PM, Sergey V. wrote: > Good day, > > I'm trying to figure out how to do something similar to the Symmetric > Encryption recipe (http://www.sqlalchemy.org/trac/wiki/UsageRecipes/ > SymmetricEncryption), only on the database side, not in Python. > > I have a suspicion that @compiles decorator may provide a solution, > but having trouble understaning how to apply it to my case. > > For simplicity, let's imagine a field which stores data in upper case > but always returns it in lower case... so it needs to generate SQL > similar to > > "INSERT INTO tablename VALUES (..., upper(...), ...)"
this can be assigned, (1) i.e. myobject.fieldname = func.upper(somename) which you can apply with a @validates decorator (2) > > on insert and > > "SELECT ..., lower(fieldname) as fieldname, ... FROM tablename" for this you'd use column_property(). (3) for the SQL functions themselves we're using func (4) 1: http://www.sqlalchemy.org/docs/orm/session.html#embedding-sql-insert-update-expressions-into-a-flush 2: http://www.sqlalchemy.org/docs/orm/mapper_config.html#simple-validators 3: http://www.sqlalchemy.org/docs/orm/mapper_config.html#sql-expressions-as-mapped-attributes 4: http://www.sqlalchemy.org/docs/core/expression_api.html#sqlalchemy.sql.expression.func For a slightly old example of some of this kind of thing (probably more complicated than you'd need here), see the PostGIS example under examples/postgis/. -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to sqlalchemy@googlegroups.com. To unsubscribe from this group, send email to sqlalchemy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en.
