← Back to branch summary

~ubuntu-branches/debian/jessie/sqlalchemy/jessie

« back to all changes in this revision

Viewing changes to examples/dogpile_caching/helloworld.py

  • Committer: Package Import Robot
  • Author(s): Piotr Ożarowski, Jakub Wilk, Piotr Ożarowski
  • Date: 2013-07-06 20:53:52 UTC
  • mfrom: (1.4.23) (16.1.17 experimental)
  • Revision ID: package-import@ubuntu.com-20130706205352-ryppl1eto3illd79
Tags: 0.8.2-1
[ Jakub Wilk ]
* Use canonical URIs for Vcs-* fields.

[ Piotr Ożarowski ]
* New upstream release
* Upload to unstable
* Build depend on python3-all instead of -dev, extensions are not built for
  Python 3.X 

Show diffs side-by-side

added added

removed removed

Lines of Context:
examples/dogpile_caching/helloworld.py
 
1
"""helloworld.py
 
2
 
 
3
Illustrate how to load some data, and cache the results.
 
4
 
 
5
"""
 
6
 
 
7
from environment import Session
 
8
from model import Person
 
9
from caching_query import FromCache
 
10
 
 
11
# load Person objects.  cache the result under the namespace "all_people".
 
12
print "loading people...."
 
13
people = Session.query(Person).options(FromCache("default")).all()
 
14
 
 
15
# remove the Session.  next query starts from scratch.
 
16
Session.remove()
 
17
 
 
18
# load again, using the same FromCache option. now they're cached
 
19
# under "all_people", no SQL is emitted.
 
20
print "loading people....again!"
 
21
people = Session.query(Person).options(FromCache("default")).all()
 
22
 
 
23
# want to load on some different kind of query ?  change the namespace
 
24
# you send to FromCache
 
25
print "loading people two through twelve"
 
26
people_two_through_twelve = Session.query(Person).\
 
27
                            options(FromCache("default")).\
 
28
                            filter(Person.name.between("person 02", "person 12")).\
 
29
                            all()
 
30
 
 
31
# the data is cached under the "namespace" you send to FromCache, *plus*
 
32
# the bind parameters of the query.    So this query, having
 
33
# different literal parameters under "Person.name.between()" than the
 
34
# previous one, issues new SQL...
 
35
print "loading people five through fifteen"
 
36
people_five_through_fifteen = Session.query(Person).\
 
37
                            options(FromCache("default")).\
 
38
                            filter(Person.name.between("person 05", "person 15")).\
 
39
                            all()
 
40
 
 
41
 
 
42
# ... but using the same params as are already cached, no SQL
 
43
print "loading people two through twelve...again!"
 
44
people_two_through_twelve = Session.query(Person).\
 
45
                            options(FromCache("default")).\
 
46
                            filter(Person.name.between("person 02", "person 12")).\
 
47
                            all()
 
48
 
 
49
 
 
50
# invalidate the cache for the three queries we've done.  Recreate
 
51
# each Query, which includes at the very least the same FromCache,
 
52
# same list of objects to be loaded, and the same parameters in the
 
53
# same order, then call invalidate().
 
54
print "invalidating everything"
 
55
Session.query(Person).options(FromCache("default")).invalidate()
 
56
Session.query(Person).\
 
57
            options(FromCache("default")).\
 
58
            filter(Person.name.between("person 02", "person 12")).invalidate()
 
59
Session.query(Person).\
 
60
            options(FromCache("default", "people_on_range")).\
 
61
            filter(Person.name.between("person 05", "person 15")).invalidate()
 
62