On Thu, Mar 28, 2019 at 5:33 PM Jonathan Vanasco <[email protected]> wrote: > > I gave up on attempts to do something similar a while back, because it became > to problematic to examine all the SqlAlchemy objects – and the existing query > – in an effort to construct the joins and query correctly. > > I would up using a two-phase approach. phase 1 analyzes the 'requested > metrics' to figure out which tables and columns are needed, and raises an > error if things look bad. phase 2 generates the query. I use a python dict > to store metadata about the query as it is analyzed, using the tables as keys > and building an array of the columns - this way i only join the table once. > based on what tables are needed in the dict, or other data on the metrics I > pre-calculate, i know how to structure the joins. this approach is somewhat > restricting, but works very well, is quick to deploy and easy to maintain.
is this some standard thing you're both doing? I didn't see anything about joins or query analyzing. you often have answers for questions where I don't understand what theyre asking! > > -- > 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 [email protected]. > To post to this group, send email to [email protected]. > Visit this group at https://groups.google.com/group/sqlalchemy. > For more options, visit https://groups.google.com/d/optout. -- 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 [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
