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Fix ON DELETE CASCADE issue on relationships

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This commit is contained in:
Lucas Verney 2015-12-25 22:07:06 +01:00
parent e7332e3b91
commit f67495bd38
1 changed files with 19 additions and 10 deletions
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29
database.py
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@ -1,6 +1,8 @@
"""
This file contains the database schema in SQLAlchemy format.
"""
import sqlite3
from sqlalchemy import event
from sqlalchemy import Column, ForeignKey, Integer, String
from sqlalchemy.engine import Engine
@ -15,12 +17,13 @@ def set_sqlite_pragma(dbapi_connection, connection_record):
"""
Auto enable foreign keys for SQLite.
"""
cursor = dbapi_connection.cursor()
cursor.execute("PRAGMA foreign_keys=ON")
cursor.close()
# Play well with other DB backends
if type(dbapi_connection) is sqlite3.Connection:
cursor = dbapi_connection.cursor()
cursor.execute("PRAGMA foreign_keys=ON")
cursor.close()
# TODO: Backref
class Association(Base):
# Relationships are to be read "left RELATION right"
__tablename__ = "association"
@ -32,12 +35,15 @@ class Association(Base):
ondelete="CASCADE"))
right_paper = sqlalchemy_relationship("Paper",
foreign_keys=right_id,
back_populates="related_by")
relationship = sqlalchemy_relationship("Relationship")
back_populates="related_by",
passive_deletes=True)
relationship = sqlalchemy_relationship("Relationship",
passive_deletes=True)
left_paper = sqlalchemy_relationship("Paper",
foreign_keys=left_id,
back_populates="related_to")
back_populates="related_to",
passive_deletes=True)
class Paper(Base):
@ -48,11 +54,13 @@ class Paper(Base):
# related_to are papers related to this paper (this_paper R …)
related_to = sqlalchemy_relationship("Association",
foreign_keys="Association.left_id",
back_populates="left_paper")
back_populates="left_paper",
passive_deletes=True)
# related_by are papers referenced by this paper (… R this_paper)
related_by = sqlalchemy_relationship("Association",
foreign_keys="Association.right_id",
back_populates="right_paper")
back_populates="right_paper",
passive_deletes=True)
def __repr__(self):
return "<Paper(id='%d', doi='%s', arxiv_id='%s')>" % (
@ -95,4 +103,5 @@ class Relationship(Base):
id = Column(Integer, primary_key=True)
name = Column(String(), unique=True)
associations = sqlalchemy_relationship("Association",
back_populates="relationship")
back_populates="relationship",
passive_deletes=True)