Ticket #851: sqlaccess.py

File sqlaccess.py, 3.2 KB (added by aaronsw, 19 years ago)

Patch to proxy thd new SQL API to the old

Line 
1# TODO:
2# - automatically .save() by default (although you can turn it off)
3# - Map all Django lookup types
4# - Map all Django lookup functions
5
6mapping = {
7 '>': 'gt',
8 '<': 'lt',
9 '>=': 'ge',
10 '<=': 'le',
11 '==': 'eq',
12 '!=': 'ne'
13}
14
15u_mapping = {
16 '+': 'pos',
17 '-': 'neg',
18 '~': 'inv'
19}
20
21class Atom:
22 def __init__(self, start=(), modifiers=None):
23 self._start = start
24 self._modifiers = modifiers
25
26 def makefunc(self, key):
27 return lambda x: Statement(self, key, x)
28
29 def u_makefunc(self, key):
30 return lambda x: Atom(self._start, key)
31
32 for (key,val) in mapping.items():
33 setattr(self, '__'+val+'__', makefunc(self, key))
34
35 for (key,val) in u_mapping.items():
36 setattr(self, '__'+val+'__', u_makefunc(self, key))
37
38 def __pos__(self): return Atom(self._start, '+')
39
40 def __getattr__(self, x):
41 if x.startswith('_'): return x.__dict__[x]
42 return Atom(self._start+(x,))
43
44 def __repr__(self): return '.'.join(self._start)
45
46 def _django(self): return '__'.join(self._start)
47
48class Statement:
49 def __init__(self, atom, operator, value):
50 self._atom = atom
51 self._operator = operator
52 self._value = value
53
54 if isinstance(value, Atom) and value._modifiers:
55 self._operator += value._modifiers
56
57 def __and__(self, x): return Group(self, 'and', x)
58 def __or__(self, x): return Group(self, 'or', y)
59
60 def __repr__(self):
61 return repr(self._atom) + ' ' + self._operator + ' ' +repr(self._value)
62
63 def _django(self):
64 mapping = {
65 '>': 'gt',
66 '<': 'lt',
67 '>=': 'gte',
68 '<=': 'lte',
69 '==': 'exact',
70 '!=': 'ne'
71 }
72
73 return {self._atom._django() + '__' + mapping[self._operator]:self._value}
74
75class Group:
76 def __init__(self, stmt1, operator, stmt2):
77 self._stmt1 = stmt1
78 self._operator = operator
79 self._stmt2 = stmt2
80
81 def __repr__(self):
82 return '('+repr(self._stmt1)+') ' + self._operator + ' ('+repr(self._stmt2)+')'
83
84 def _django(self):
85 if self._operator == 'and':
86 return self._stmt1._django() + self._stmt2._django()
87 else:
88 raise "I don't think Django supports that operator."
89
90q = Atom()
91
92## django-specific below this line
93
94class Table:
95 def __init__(self, table):
96 self.table = table
97
98 def get(self, *args):
99 query = {}
100 for x in args:
101 query.update(x._django())
102 return Result(self.table, query)
103
104class Result:
105 def __init__(self, table, query):
106 self.table = table
107 self.query = query
108
109 def __getitem__(self, x):
110 if x == 0: return self.table.get_object(**self.query)
111 else:
112 iterator = self.table.get_iterator(**self.query)
113 i = -1
114 while i != x:
115 iterator.next()
116 i += 1
117 return iterator.next()
118
119 def __len__(self): return self.table.get_count(**self.query)
120
121 def __iter__(self):
122 return self.table.get_iterator(**self.query)
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