Ticket #87: oracle.py

File oracle.py, 5.1 KB (added by Jason Huggins, 15 years ago)

New db backend for Oracle.

Line 
1"""
2Oracle database backend for Django.
3
4Requires cx_Oracle: http://www.computronix.com/utilities.shtml
5"""
6
7from django.core.db import base, typecasts
8import cx_Oracle  as Database
9
10#needed for fetchone, fetchmany, fetchall support
11from django.core.db.dicthelpers import *
12
13
14DatabaseError = Database.DatabaseError
15
16class DatabaseWrapper:
17    def __init__(self):
18        self.connection = None
19        self.queries = []
20
21    def cursor(self):
22        from django.conf.settings import DATABASE_USER, DATABASE_NAME, DATABASE_HOST, DATABASE_PASSWORD, DEBUG
23        if self.connection is None:
24            if DATABASE_NAME == '' or DATABASE_USER == '' or DATABASE_PASSWORD == '':
25                from django.core.exceptions import ImproperlyConfigured
26                raise ImproperlyConfigured, "You need to specify DATABASE_NAME, DATABASE_USER, and DATABASE_PASSWORD in your Django settings file."
27            conn_string = "%s/%s@%s" % (DATABASE_USER, DATABASE_PASSWORD, DATABASE_NAME)
28            self.connection = Database.connect(conn_string)               
29        return FormatStylePlaceholderCursor(self.connection)
30
31    def commit(self):
32        self.connection.commit()
33
34    def rollback(self):
35        if self.connection:
36            self.connection.rollback()
37
38    def close(self):
39        if self.connection is not None:
40            self.connection.close()
41            self.connection = None
42
43class FormatStylePlaceholderCursor(Database.Cursor):
44    """
45    Django uses "format" (e.g. '%s') style placeholders, but Oracle uses ":var" style.
46    This fixes it -- but note that if you want to use a literal "%s" in a query,
47    you'll need to use "%%s" (which I belive is true of other wrappers as well).
48    """
49   
50    def execute(self, query, params=[]):
51        query = self.convert_arguments(query, len(params))
52        return Database.Cursor.execute(self, query, params)
53       
54    def executemany(self, query, params=[]):         
55        query = self.convert_arguments(query, len(params[0]))
56        return Database.Cursor.executemany(self, query, params)
57       
58    def convert_arguments(self, query, num_params):
59        # replace occurances of "%s" with ":arg" - Oracle requires colons for parameter placeholders.
60        args = [':arg' for i in range(num_params)]
61        return query % tuple(args)
62
63def get_last_insert_id(cursor, table_name, pk_name):
64    query = "SELECT %s_sq.currval from dual" % table_name
65    cursor.execute(query)
66    return cursor.fetchone()[0]
67
68def get_date_extract_sql(lookup_type, table_name):
69    raise NotImplementedError
70
71def get_date_trunc_sql(lookup_type, field_name):
72    raise NotImplementedError
73   
74def get_table_list(cursor):
75    "Returns a list of table names in the current database."
76    raise NotImplementedError
77
78def get_relations(cursor, table_name):
79    """
80    Returns a dictionary of {field_index: (field_index_other_table, other_table)}
81    representing all relationships to the given table. Indexes are 0-based.
82    """
83    raise NotImplementedError
84
85
86OPERATOR_MAPPING = {
87    'exact': '=',
88    'iexact': 'LIKE',
89    'contains': 'LIKE',
90    'icontains': 'LIKE',
91    'ne': '!=',
92    'gt': '>',
93    'gte': '>=',
94    'lt': '<',
95    'lte': '<=',
96    'startswith': 'LIKE',
97    'endswith': 'LIKE',
98    'istartswith': 'LIKE',
99    'iendswith': 'LIKE',
100}
101
102# This dictionary maps Field objects to their associated MySQL column
103# types, as strings. Column-type strings can contain format strings; they'll
104# be interpolated against the values of Field.__dict__ before being output.
105# If a column type is set to None, it won't be included in the output.
106DATA_TYPES = {
107    'AutoField':         'number(38)',
108    'BooleanField':      'number(1)',
109    'CharField':         'varchar2(%(maxlength)s)',
110    'CommaSeparatedIntegerField': 'varchar2(%(maxlength)s)',
111    'DateField':         'date',
112    'DateTimeField':     'date',
113    'EmailField':        'varchar2(75)',
114    'FileField':         'varchar2(100)',
115    'FloatField':        'number(%(max_digits)s, %(decimal_places)s)',
116    'ImageField':        'varchar2(100)',
117    'IntegerField':      'integer',
118    'IPAddressField':    'char(15)',
119    'ManyToManyField':   None,
120    'NullBooleanField':  'integer',
121    'OneToOneField':     'integer',
122    'PhoneNumberField':  'varchar(20)',
123    'PositiveIntegerField': 'integer',
124    'PositiveSmallIntegerField': 'smallint',
125    'SlugField':         'varchar(50)',
126    'SmallIntegerField': 'smallint',
127    'TextField':         'long',
128    'TimeField':         'timestamp',
129    'URLField':          'varchar(200)',
130    'USStateField':      'varchar(2)',
131    'XMLField':          'long',
132}
133
134# Maps type codes to Django Field types.
135DATA_TYPES_REVERSE = {
136    16: 'BooleanField',
137    21: 'SmallIntegerField',
138    23: 'IntegerField',
139    25: 'TextField',
140    869: 'IPAddressField',
141    1043: 'CharField',
142    1082: 'DateField',
143    1083: 'TimeField',
144    1114: 'DateTimeField',
145    1184: 'DateTimeField',
146    1266: 'TimeField',
147    1700: 'FloatField',
148}
149
150EMPTY_STR_EQUIV = ' '
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