app/django/db/backends/postgresql_psycopg2/introspection.py
author Daniel Bentley <dbentley@google.com>
Sun, 12 Apr 2009 09:06:45 +0000
branchgae-fetch-limitation-fix
changeset 2313 c39a81bce1bd
parent 323 ff1a9aa48cfd
permissions -rw-r--r--
Use offset_linkid instead of offset to scan >1000 entities. this is a first-cut. It works in all the ways I could make earlier versions fail. It passes link_id as URL parameters. It also has a new class LinkCreator which makes the main body of getListContents even easier to write. I wasn't sure if link_id's could have non alphanumeric characters; if so, they need to be URL encoded/decoded. I also need to go and remove any mention of raw offsets now, because we don't use them. I believe I've talked about this approach with a few of you and it sounded reasonable. Feel free to roll-back/fix/amend/comment-for-me-to-fix. This is my first big-logic-change to Melange. Patch by: Dan Bentley
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
323
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents: 54
diff changeset
     1
from django.db.backends.postgresql.introspection import DatabaseIntrospection as PostgresDatabaseIntrospection
54
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
     2
323
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents: 54
diff changeset
     3
class DatabaseIntrospection(PostgresDatabaseIntrospection):
54
03e267d67478 Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff changeset
     4
323
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents: 54
diff changeset
     5
    def get_relations(self, cursor, table_name):
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents: 54
diff changeset
     6
        """
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents: 54
diff changeset
     7
        Returns a dictionary of {field_index: (field_index_other_table, other_table)}
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents: 54
diff changeset
     8
        representing all relationships to the given table. Indexes are 0-based.
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents: 54
diff changeset
     9
        """
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents: 54
diff changeset
    10
        cursor.execute("""
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents: 54
diff changeset
    11
            SELECT con.conkey, con.confkey, c2.relname
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents: 54
diff changeset
    12
            FROM pg_constraint con, pg_class c1, pg_class c2
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents: 54
diff changeset
    13
            WHERE c1.oid = con.conrelid
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents: 54
diff changeset
    14
                AND c2.oid = con.confrelid
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents: 54
diff changeset
    15
                AND c1.relname = %s
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents: 54
diff changeset
    16
                AND con.contype = 'f'""", [table_name])
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents: 54
diff changeset
    17
        relations = {}
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents: 54
diff changeset
    18
        for row in cursor.fetchall():
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents: 54
diff changeset
    19
            # row[0] and row[1] are single-item lists, so grab the single item.
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents: 54
diff changeset
    20
            relations[row[0][0] - 1] = (row[1][0] - 1, row[2])
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents: 54
diff changeset
    21
        return relations