1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
|
# $Id$
import MySQLdb
def connect(cfg, section="sql"):
"""Connect to a MySQL database using connection parameters from an
rpki.config.parser object.
"""
return MySQLdb.connect(user = cfg.get(section, "sql-username"),
db = cfg.get(section, "sql-database"),
passwd = cfg.get(section, "sql-password"))
class sql_persistant(object):
"""Mixin for persistant class that needs to be stored in SQL.
"""
## @var sql_children
# Dictionary listing this class's children in the tree of SQL
# tables. Key is the class object of a child, value is the name of
# the attribute in this class at which a list of the resulting child
# objects are stored.
sql_children = {}
@classmethod
def sql_fetch(cls, db, **kwargs):
"""Fetch rows from SQL based on a canned query and a set of
keyword arguments, and instantiate them as objects, returning a
list of the instantiated objects.
This is a class method because in general we don't even know how
many matches the SQL lookup will return until after we've
performed it.
"""
cur = db.cursor()
cur.execute(self.sql_fetch_cmd % kwargs)
rows = cur.fetchall()
cur.close()
objs = []
for row in rows:
obj = cls()
obj.sql_objectify(row)
objs.append(obj)
if isinstance(obj, sql_persistant):
for kid in obj.sql_children:
setattr(obj, obj.sql_children[kid], kid.sql_fetch(db))
return objs
def sql_objectify(self, row):
"""Initialize self with values returned by self.sql_fetch().
This method is also responsible for performing the
fetch/objectify() cycle on any of its children in the tree of
classes representing SQL tables in this database. But I'm trying
to move that responsibility to self.sql_fetch()....
"""
raise NotImplementedError
|
