- converted beaker demo to dogpile.cache, [ticket:2589]

1 files changed, 62 insertions, 0 deletions

diff --git a/examples/dogpile_caching/helloworld.py b/examples/dogpile_caching/helloworld.py
new file mode 100644
index 000000000..e2e4d4f78
--- /dev/null
+++ b/examples/dogpile_caching/helloworld.py
@@ -0,0 +1,62 @@
+"""helloworld.py
+
+Illustrate how to load some data, and cache the results.
+
+"""
+
+from environment import Session
+from model import Person
+from caching_query import FromCache
+
+# load Person objects.  cache the result under the namespace "all_people".
+print "loading people...."
+people = Session.query(Person).options(FromCache("default")).all()
+
+# remove the Session.  next query starts from scratch.
+Session.remove()
+
+# load again, using the same FromCache option. now they're cached
+# under "all_people", no SQL is emitted.
+print "loading people....again!"
+people = Session.query(Person).options(FromCache("default")).all()
+
+# want to load on some different kind of query ?  change the namespace
+# you send to FromCache
+print "loading people two through twelve"
+people_two_through_twelve = Session.query(Person).\
+                            options(FromCache("default")).\
+                            filter(Person.name.between("person 02", "person 12")).\
+                            all()
+
+# the data is cached under the "namespace" you send to FromCache, *plus*
+# the bind parameters of the query.    So this query, having
+# different literal parameters under "Person.name.between()" than the
+# previous one, issues new SQL...
+print "loading people five through fifteen"
+people_five_through_fifteen = Session.query(Person).\
+                            options(FromCache("default")).\
+                            filter(Person.name.between("person 05", "person 15")).\
+                            all()
+
+
+# ... but using the same params as are already cached, no SQL
+print "loading people two through twelve...again!"
+people_two_through_twelve = Session.query(Person).\
+                            options(FromCache("default")).\
+                            filter(Person.name.between("person 02", "person 12")).\
+                            all()
+
+
+# invalidate the cache for the three queries we've done.  Recreate
+# each Query, which includes at the very least the same FromCache,
+# same list of objects to be loaded, and the same parameters in the
+# same order, then call invalidate().
+print "invalidating everything"
+Session.query(Person).options(FromCache("default")).invalidate()
+Session.query(Person).\
+            options(FromCache("default")).\
+            filter(Person.name.between("person 02", "person 12")).invalidate()
+Session.query(Person).\
+            options(FromCache("default", "people_on_range")).\
+            filter(Person.name.between("person 05", "person 15")).invalidate()
+