app/django/db/backends/postgresql_psycopg2/introspection.py
author Sverre Rabbelier <srabbelier@gmail.com>
Mon, 13 Apr 2009 15:31:39 +0000
changeset 2177 e2c193e1f631
parent 323 ff1a9aa48cfd
permissions -rw-r--r--
Do not rely on dicts.merge to change target Also make dicts.merge actually not touch target. This is much cleaner than modifying in place, especially since we assign the result of the dicts.merge call to target most of the time anyway. Patch by: Sverre Rabbelier

from django.db.backends.postgresql.introspection import DatabaseIntrospection as PostgresDatabaseIntrospection

class DatabaseIntrospection(PostgresDatabaseIntrospection):

    def get_relations(self, cursor, table_name):
        """
        Returns a dictionary of {field_index: (field_index_other_table, other_table)}
        representing all relationships to the given table. Indexes are 0-based.
        """
        cursor.execute("""
            SELECT con.conkey, con.confkey, c2.relname
            FROM pg_constraint con, pg_class c1, pg_class c2
            WHERE c1.oid = con.conrelid
                AND c2.oid = con.confrelid
                AND c1.relname = %s
                AND con.contype = 'f'""", [table_name])
        relations = {}
        for row in cursor.fetchall():
            # row[0] and row[1] are single-item lists, so grab the single item.
            relations[row[0][0] - 1] = (row[1][0] - 1, row[2])
        return relations