On Fri, Apr 13, 2018 at 5:11 PM, Ashu Goel <soxfan...@gmail.com> wrote: > Hey there, > > I am trying to setup a multi-schema database, where each schema has it's own > metadata and tables, but ForeignKey constraints are allowed to cross > schemas. This usually works fine until I start introducing something like > alembic revision autogeneration, which uses the sorted_tables feature of the > metadata, in which case I get errors because sqlalchemy cannot find the > table referenced by the foreign key. I've attached a simple script that > showcases my findings, along > with the stacktrace below. I understand that a simple fix would be to use > actual model object instead of a string to reference the foreign column, but > ideally would like to continue using strings in case we ever decide to break > up the code into different projects pointing to the same database. Any > thoughts?
here are your choices: 1. put the two tables on the same MetaData object 2. use the column object in the ForeignKey, not the string 3. don't use ForeignKey. Looks like you want to use #3 because the ForeignKey construct here is completely useless without it being able to find the other Table, it's not buying you anything. > > Traceback (most recent call last): > File "simple.py", line 21, in <module> > print(metadata_two.sorted_tables) > File > "/Users/ashu/Documents/server/env/lib/python3.5/site-packages/sqlalchemy/sql/schema.py", > line 3842, in sorted_tables > return ddl.sort_tables(sorted(self.tables.values(), key=lambda t: > t.key)) > File > "/Users/ashu/Documents/server/env/lib/python3.5/site-packages/sqlalchemy/sql/ddl.py", > line 1028, in sort_tables > tables, filter_fn=_skip_fn, extra_dependencies=extra_dependencies) > File > "/Users/ashu/Documents/server/env/lib/python3.5/site-packages/sqlalchemy/sql/ddl.py", > line 1095, in sort_tables_and_constraints > dependent_on = fkc.referred_table > File > "/Users/ashu/Documents/server/env/lib/python3.5/site-packages/sqlalchemy/sql/schema.py", > line 3002, in referred_table > return self.elements[0].column.table > File > "/Users/ashu/Documents/server/env/lib/python3.5/site-packages/sqlalchemy/util/langhelpers.py", > line 767, in __get__ > obj.__dict__[self.__name__] = result = self.fget(obj) > File > "/Users/ashu/Documents/server/env/lib/python3.5/site-packages/sqlalchemy/sql/schema.py", > line 1891, in column > tablekey) > sqlalchemy.exc.NoReferencedTableError: Foreign key associated with column > 'table_two.one_id' could not find table 'one.table_one' with which to > generate a foreign key to target column 'id' > > > Thanks! > Ashu > > -- > 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. -- 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.
