Ticket #87: mysql.py

File mysql.py, 5.2 KB (added by Jason Huggins, 15 years ago)
Line 
1"""
2MySQL database backend for Django.
3
4Requires MySQLdb: http://sourceforge.net/projects/mysql-python
5"""
6
7from django.core.db import base, typecasts
8from django.core.db.dicthelpers import *
9import MySQLdb as Database
10from MySQLdb.converters import conversions
11from MySQLdb.constants import FIELD_TYPE
12import types
13
14DatabaseError = Database.DatabaseError
15
16django_conversions = conversions.copy()
17django_conversions.update({
18    types.BooleanType: typecasts.rev_typecast_boolean,
19    FIELD_TYPE.DATETIME: typecasts.typecast_timestamp,
20    FIELD_TYPE.DATE: typecasts.typecast_date,
21    FIELD_TYPE.TIME: typecasts.typecast_time,
22})
23
24class DatabaseWrapper:
25    def __init__(self):
26        self.connection = None
27        self.queries = []
28
29    def cursor(self):
30        from django.conf.settings import DATABASE_USER, DATABASE_NAME, DATABASE_HOST, DATABASE_PASSWORD, DEBUG
31        if self.connection is None:
32            self.connection = Database.connect(user=DATABASE_USER, db=DATABASE_NAME,
33                passwd=DATABASE_PASSWORD, host=DATABASE_HOST, conv=django_conversions)
34        if DEBUG:
35            return base.CursorDebugWrapper(self.connection.cursor(), self)
36        return self.connection.cursor()
37
38    def commit(self):
39        self.connection.commit()
40
41    def rollback(self):
42        if self.connection:
43            try:
44                self.connection.rollback()
45            except Database.NotSupportedError:
46                pass
47
48    def close(self):
49        if self.connection is not None:
50            self.connection.close()
51            self.connection = None
52
53def get_last_insert_id(cursor, table_name, pk_name):
54    cursor.execute("SELECT LAST_INSERT_ID()")
55    return cursor.fetchone()[0]
56
57def get_date_extract_sql(lookup_type, table_name):
58    # lookup_type is 'year', 'month', 'day'
59    # http://dev.mysql.com/doc/mysql/en/date-and-time-functions.html
60    return "EXTRACT(%s FROM %s)" % (lookup_type.upper(), table_name)
61
62def get_date_trunc_sql(lookup_type, field_name):
63    # lookup_type is 'year', 'month', 'day'
64    # http://dev.mysql.com/doc/mysql/en/date-and-time-functions.html
65    # MySQL doesn't support DATE_TRUNC, so we fake it by subtracting intervals.
66    # If you know of a better way to do this, please file a Django ticket.
67    subtractions = ["interval (DATE_FORMAT(%s, '%%%%s')) second - interval (DATE_FORMAT(%s, '%%%%i')) minute - interval (DATE_FORMAT(%s, '%%%%H')) hour" % (field_name, field_name, field_name)]
68    if lookup_type in ('year', 'month'):
69        subtractions.append(" - interval (DATE_FORMAT(%s, '%%%%e')-1) day" % field_name)
70    if lookup_type == 'year':
71        subtractions.append(" - interval (DATE_FORMAT(%s, '%%%%m')-1) month" % field_name)
72    return "(%s - %s)" % (field_name, ''.join(subtractions))
73
74def get_table_list(cursor):
75    "Returns a list of table names in the current database."
76    cursor.execute("SHOW TABLES")
77    return [row[0] for row in cursor.fetchall()]
78
79def get_relations(cursor, table_name):
80    raise NotImplementedError
81
82OPERATOR_MAPPING = {
83    'exact': '=',
84    'iexact': 'LIKE',
85    'contains': 'LIKE',
86    'icontains': 'LIKE',
87    'ne': '!=',
88    'gt': '>',
89    'gte': '>=',
90    'lt': '<',
91    'lte': '<=',
92    'startswith': 'LIKE',
93    'endswith': 'LIKE',
94    'istartswith': 'LIKE',
95    'iendswith': 'LIKE',
96}
97
98# This dictionary maps Field objects to their associated MySQL column
99# types, as strings. Column-type strings can contain format strings; they'll
100# be interpolated against the values of Field.__dict__ before being output.
101# If a column type is set to None, it won't be included in the output.
102DATA_TYPES = {
103    'AutoField':         'mediumint(9) unsigned auto_increment',
104    'BooleanField':      'bool',
105    'CharField':         'varchar(%(maxlength)s)',
106    'CommaSeparatedIntegerField': 'varchar(%(maxlength)s)',
107    'DateField':         'date',
108    'DateTimeField':     'datetime',
109    'EmailField':        'varchar(75)',
110    'FileField':         'varchar(100)',
111    'FloatField':        'numeric(%(max_digits)s, %(decimal_places)s)',
112    'ImageField':        'varchar(100)',
113    'IntegerField':      'integer',
114    'IPAddressField':    'char(15)',
115    'ManyToManyField':   None,
116    'NullBooleanField':  'bool',
117    'OneToOneField':     'integer',
118    'PhoneNumberField':  'varchar(20)',
119    'PositiveIntegerField': 'integer UNSIGNED',
120    'PositiveSmallIntegerField': 'smallint UNSIGNED',
121    'SlugField':         'varchar(50)',
122    'SmallIntegerField': 'smallint',
123    'TextField':         'text',
124    'TimeField':         'time',
125    'URLField':          'varchar(200)',
126    'USStateField':      'varchar(2)',
127    'XMLField':          'text',
128}
129
130DATA_TYPES_REVERSE = {
131    FIELD_TYPE.BLOB: 'TextField',
132    FIELD_TYPE.CHAR: 'CharField',
133    FIELD_TYPE.DECIMAL: 'FloatField',
134    FIELD_TYPE.DATE: 'DateField',
135    FIELD_TYPE.DATETIME: 'DateTimeField',
136    FIELD_TYPE.DOUBLE: 'FloatField',
137    FIELD_TYPE.FLOAT: 'FloatField',
138    FIELD_TYPE.INT24: 'IntegerField',
139    FIELD_TYPE.LONG: 'IntegerField',
140    FIELD_TYPE.LONGLONG: 'IntegerField',
141    FIELD_TYPE.SHORT: 'IntegerField',
142    FIELD_TYPE.STRING: 'TextField',
143    FIELD_TYPE.TIMESTAMP: 'DateTimeField',
144    FIELD_TYPE.TINY_BLOB: 'TextField',
145    FIELD_TYPE.MEDIUM_BLOB: 'TextField',
146    FIELD_TYPE.LONG_BLOB: 'TextField',
147    FIELD_TYPE.VAR_STRING: 'CharField',
148}
149
150EMPTY_STR_EQUIV = ''
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