Mike, Thanks for your careful analysis and thoughtful comments. I appreciate the time you spent to think about this. I agree that this does represent simpler syntax for a narrow class of common operations. Per your advice, I'll work this up into a package and post it on pypi. Thanks for the feedback!
Bryan On Thursday, June 15, 2017 at 3:11:47 PM UTC-5, Bryan Jones wrote: > > All, > > While working on my SQLAlchemy-based application, I noticed an opportunity > to provide a more concise, Pythonic query syntax. For example, > User['jack'].addresses produces a Query for the Address of a User named > jack. I had two questions > > 1. Has someone already done this? If so, would you provide a link? > 2. If not, would this be reasonable for inclusion in SQLAlchemy, > either as an ORM example, or as a part of the core code base? If so, I can > submit a pull request. > > A quick comparison of this statement to the traditional approach: > > User ['jack'] .addresses > Query([]).select_from(User).filter(User.name == 'jack').join(Address). > add_entity(Address) > > A few more (complete) examples of this approach: > # Ask for the full User object for jack. > User['jack'].to_query(session) > # Ask only for Jack's full name. > User['jack'].fullname.to_query(session) > # Get all of Jack's addresses. > User['jack'].addresses.to_query(session) > # Get just the email-address of all of Jack's addresses. > User['jack'].addresses.email_address.to_query(session) > # Get just the email-address j...@yahoo.com of Jack's addresses. > User['jack'].addresses['j...@yahoo.com'].to_query(session) > # Ask for the full Address object for j...@yahoo.com. > Address['j...@yahoo.com'].to_query(session) > # Ask for the User associated with this address. > Address['j...@yahoo.com'].user.to_query(session) > # Use a filter criterion to select a User with a full name of Jack Bean. > User[User.fullname == 'Jack Bean'].to_query(session) > # Use two filter criteria to find the user named jack with a full name of > Jack Bean. > User['jack'][User.fullname == 'Jack Bean'].to_query(session) > # Look for the user with id 1. > User[1].to_query(session) > > Tested on Python 3.6.1, Windows 10, SQLAlchemy 1.1.10. I've attached the > code, and a HTML document of the code with helpful hyperlinks. > > Bryan > -- > Bryan A. Jones, Ph.D. > Associate Professor > Department of Electrical and Computer Engineering > 231 Simrall / PO Box 9571 > Mississippi State University > Mississippi State, MS 39762 > http://www.ece.msstate.edu/~bjones > bjones AT ece DOT msstate DOT edu > voice 662-325-3149 > fax 662-325-2298 > > Our Master, Jesus Christ, is on his way. He'll show up right on > time, his arrival guaranteed by the Blessed and Undisputed Ruler, > High King, High God. > - 1 Tim. 6:14b-15 (The Message) > -- 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.
