Hello all, I am in the process of trying to create a dynamic expression query engine in an application I'm working on.
So there is a formula that gets defined like so: formula = '"metric:123" + "metric:456" + "metric:789"' Each metric maps to a column in the database tables - long story short, I'm able to retrieve the metric by ID, and instantiate an InstrumentedAttribute object that has the SQLAlchemy metadata for the associated column. What I'm trying to achieve is to be able to iterate through the formula, and dynamically build a SQLALchemy query that maps to the formula. For example, the formula defined above would look something like this in SQL: SELECT post.id + campaign.id + asset.id FROM post, campaign, asset WHERE ......; The idea is to translate the above to something like: session.query(<sqlalchemy.orm.attributes.InstrumentedAttribute object at 0x7ff9269f92b0> + <sqlalchemy.orm.attributes.InstrumentedAttribute object at 0x7ff9269c5990> + <sqlalchemy.orm.attributes.InstrumentedAttribute object at 0x7ff926896048>).all() I've tried a couple of approaches of dynamically generating the SQLAlchemy ORM query, but I haven't been able to find anything that works. Would anyone have any idea or tips on how to accomplish this? Thank you! -- SQLAlchemy - The Python SQL Toolkit and Object Relational Mapper http://www.sqlalchemy.org/ To post example code, please provide an MCVE: Minimal, Complete, and Verifiable Example. See http://stackoverflow.com/help/mcve for a full description. --- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at https://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
