author | Lennard de Rijk <ljvderijk@gmail.com> |
Thu, 12 Feb 2009 23:12:09 +0000 | |
changeset 1289 | 86a4e0e75ea6 |
parent 323 | ff1a9aa48cfd |
permissions | -rw-r--r-- |
54
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
1 |
""" |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
2 |
Various data structures used in query construction. |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
3 |
|
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
4 |
Factored out from django.db.models.query so that they can also be used by other |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
5 |
modules without getting into circular import difficulties. |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
6 |
""" |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
7 |
|
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
8 |
from copy import deepcopy |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
9 |
|
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
10 |
from django.utils import tree |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
11 |
|
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
12 |
class QueryWrapper(object): |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
13 |
""" |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
14 |
A type that indicates the contents are an SQL fragment and the associate |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
15 |
parameters. Can be used to pass opaque data to a where-clause, for example. |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
16 |
""" |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
17 |
def __init__(self, sql, params): |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
18 |
self.data = sql, params |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
19 |
|
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
20 |
class Q(tree.Node): |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
21 |
""" |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
22 |
Encapsulates filters as objects that can then be combined logically (using |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
23 |
& and |). |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
24 |
""" |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
25 |
# Connection types |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
26 |
AND = 'AND' |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
27 |
OR = 'OR' |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
28 |
default = AND |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
29 |
|
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
30 |
def __init__(self, *args, **kwargs): |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
31 |
super(Q, self).__init__(children=list(args) + kwargs.items()) |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
32 |
|
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
33 |
def _combine(self, other, conn): |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
34 |
if not isinstance(other, Q): |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
35 |
raise TypeError(other) |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
36 |
obj = deepcopy(self) |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
37 |
obj.add(other, conn) |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
38 |
return obj |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
39 |
|
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
40 |
def __or__(self, other): |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
41 |
return self._combine(other, self.OR) |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
42 |
|
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
43 |
def __and__(self, other): |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
44 |
return self._combine(other, self.AND) |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
45 |
|
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
46 |
def __invert__(self): |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
47 |
obj = deepcopy(self) |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
48 |
obj.negate() |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
49 |
return obj |
03e267d67478
Major reorganization of the soc svn repo, to merge into a single App Engine
Todd Larsen <tlarsen@google.com>
parents:
diff
changeset
|
50 |
|
323
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
54
diff
changeset
|
51 |
def select_related_descend(field, restricted, requested): |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
54
diff
changeset
|
52 |
""" |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
54
diff
changeset
|
53 |
Returns True if this field should be used to descend deeper for |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
54
diff
changeset
|
54 |
select_related() purposes. Used by both the query construction code |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
54
diff
changeset
|
55 |
(sql.query.fill_related_selections()) and the model instance creation code |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
54
diff
changeset
|
56 |
(query.get_cached_row()). |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
54
diff
changeset
|
57 |
""" |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
54
diff
changeset
|
58 |
if not field.rel: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
54
diff
changeset
|
59 |
return False |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
54
diff
changeset
|
60 |
if field.rel.parent_link: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
54
diff
changeset
|
61 |
return False |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
54
diff
changeset
|
62 |
if restricted and field.name not in requested: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
54
diff
changeset
|
63 |
return False |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
54
diff
changeset
|
64 |
if not restricted and field.null: |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
54
diff
changeset
|
65 |
return False |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
54
diff
changeset
|
66 |
return True |
ff1a9aa48cfd
Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
54
diff
changeset
|
67 |