Set new Melange version number to 0-5-20090928 in app.yaml.template.
try:
# Only exists in Python 2.4+
from threading import local
except ImportError:
# Import copy of _thread_local.py from Python 2.4
from django.utils._threading_local import local
try:
set
except NameError:
# Python 2.3 compat
from sets import Set as set
from django.db.backends import util
from django.utils import datetime_safe
class BaseDatabaseWrapper(local):
"""
Represents a database connection.
"""
ops = None
def __init__(self, **kwargs):
self.connection = None
self.queries = []
self.options = kwargs
def _commit(self):
if self.connection is not None:
return self.connection.commit()
def _rollback(self):
if self.connection is not None:
return self.connection.rollback()
def _savepoint(self, sid):
if not self.features.uses_savepoints:
return
self.connection.cursor().execute(self.ops.savepoint_create_sql(sid))
def _savepoint_rollback(self, sid):
if not self.features.uses_savepoints:
return
self.connection.cursor().execute(self.ops.savepoint_rollback_sql(sid))
def _savepoint_commit(self, sid):
if not self.features.uses_savepoints:
return
self.connection.cursor().execute(self.ops.savepoint_commit_sql(sid))
def close(self):
if self.connection is not None:
self.connection.close()
self.connection = None
def cursor(self):
from django.conf import settings
cursor = self._cursor(settings)
if settings.DEBUG:
return self.make_debug_cursor(cursor)
return cursor
def make_debug_cursor(self, cursor):
return util.CursorDebugWrapper(cursor, self)
class BaseDatabaseFeatures(object):
# True if django.db.backend.utils.typecast_timestamp is used on values
# returned from dates() calls.
needs_datetime_string_cast = True
uses_custom_query_class = False
empty_fetchmany_value = []
update_can_self_select = True
interprets_empty_strings_as_nulls = False
can_use_chunked_reads = True
uses_savepoints = False
# If True, don't use integer foreign keys referring to, e.g., positive
# integer primary keys.
related_fields_match_type = False
class BaseDatabaseOperations(object):
"""
This class encapsulates all backend-specific differences, such as the way
a backend performs ordering or calculates the ID of a recently-inserted
row.
"""
def autoinc_sql(self, table, column):
"""
Returns any SQL needed to support auto-incrementing primary keys, or
None if no SQL is necessary.
This SQL is executed when a table is created.
"""
return None
def date_extract_sql(self, lookup_type, field_name):
"""
Given a lookup_type of 'year', 'month' or 'day', returns the SQL that
extracts a value from the given date field field_name.
"""
raise NotImplementedError()
def date_trunc_sql(self, lookup_type, field_name):
"""
Given a lookup_type of 'year', 'month' or 'day', returns the SQL that
truncates the given date field field_name to a DATE object with only
the given specificity.
"""
raise NotImplementedError()
def datetime_cast_sql(self):
"""
Returns the SQL necessary to cast a datetime value so that it will be
retrieved as a Python datetime object instead of a string.
This SQL should include a '%s' in place of the field's name.
"""
return "%s"
def deferrable_sql(self):
"""
Returns the SQL necessary to make a constraint "initially deferred"
during a CREATE TABLE statement.
"""
return ''
def drop_foreignkey_sql(self):
"""
Returns the SQL command that drops a foreign key.
"""
return "DROP CONSTRAINT"
def drop_sequence_sql(self, table):
"""
Returns any SQL necessary to drop the sequence for the given table.
Returns None if no SQL is necessary.
"""
return None
def field_cast_sql(self, db_type):
"""
Given a column type (e.g. 'BLOB', 'VARCHAR'), returns the SQL necessary
to cast it before using it in a WHERE statement. Note that the
resulting string should contain a '%s' placeholder for the column being
searched against.
"""
return '%s'
def fulltext_search_sql(self, field_name):
"""
Returns the SQL WHERE clause to use in order to perform a full-text
search of the given field_name. Note that the resulting string should
contain a '%s' placeholder for the value being searched against.
"""
raise NotImplementedError('Full-text search is not implemented for this database backend')
def last_executed_query(self, cursor, sql, params):
"""
Returns a string of the query last executed by the given cursor, with
placeholders replaced with actual values.
`sql` is the raw query containing placeholders, and `params` is the
sequence of parameters. These are used by default, but this method
exists for database backends to provide a better implementation
according to their own quoting schemes.
"""
from django.utils.encoding import smart_unicode, force_unicode
# Convert params to contain Unicode values.
to_unicode = lambda s: force_unicode(s, strings_only=True)
if isinstance(params, (list, tuple)):
u_params = tuple([to_unicode(val) for val in params])
else:
u_params = dict([(to_unicode(k), to_unicode(v)) for k, v in params.items()])
return smart_unicode(sql) % u_params
def last_insert_id(self, cursor, table_name, pk_name):
"""
Given a cursor object that has just performed an INSERT statement into
a table that has an auto-incrementing ID, returns the newly created ID.
This method also receives the table name and the name of the primary-key
column.
"""
return cursor.lastrowid
def lookup_cast(self, lookup_type):
"""
Returns the string to use in a query when performing lookups
("contains", "like", etc). The resulting string should contain a '%s'
placeholder for the column being searched against.
"""
return "%s"
def max_name_length(self):
"""
Returns the maximum length of table and column names, or None if there
is no limit.
"""
return None
def no_limit_value(self):
"""
Returns the value to use for the LIMIT when we are wanting "LIMIT
infinity". Returns None if the limit clause can be omitted in this case.
"""
# FIXME: API may need to change once Oracle backend is repaired.
raise NotImplementedError()
def pk_default_value(self):
"""
Returns the value to use during an INSERT statement to specify that
the field should use its default value.
"""
return 'DEFAULT'
def query_class(self, DefaultQueryClass):
"""
Given the default Query class, returns a custom Query class
to use for this backend. Returns None if a custom Query isn't used.
See also BaseDatabaseFeatures.uses_custom_query_class, which regulates
whether this method is called at all.
"""
return None
def quote_name(self, name):
"""
Returns a quoted version of the given table, index or column name. Does
not quote the given name if it's already been quoted.
"""
raise NotImplementedError()
def random_function_sql(self):
"""
Returns a SQL expression that returns a random value.
"""
return 'RANDOM()'
def regex_lookup(self, lookup_type):
"""
Returns the string to use in a query when performing regular expression
lookups (using "regex" or "iregex"). The resulting string should
contain a '%s' placeholder for the column being searched against.
If the feature is not supported (or part of it is not supported), a
NotImplementedError exception can be raised.
"""
raise NotImplementedError
def savepoint_create_sql(self, sid):
"""
Returns the SQL for starting a new savepoint. Only required if the
"uses_savepoints" feature is True. The "sid" parameter is a string
for the savepoint id.
"""
raise NotImplementedError
def savepoint_commit_sql(self, sid):
"""
Returns the SQL for committing the given savepoint.
"""
raise NotImplementedError
def savepoint_rollback_sql(self, sid):
"""
Returns the SQL for rolling back the given savepoint.
"""
raise NotImplementedError
def sql_flush(self, style, tables, sequences):
"""
Returns a list of SQL statements required to remove all data from
the given database tables (without actually removing the tables
themselves).
The `style` argument is a Style object as returned by either
color_style() or no_style() in django.core.management.color.
"""
raise NotImplementedError()
def sequence_reset_sql(self, style, model_list):
"""
Returns a list of the SQL statements required to reset sequences for
the given models.
The `style` argument is a Style object as returned by either
color_style() or no_style() in django.core.management.color.
"""
return [] # No sequence reset required by default.
def start_transaction_sql(self):
"""
Returns the SQL statement required to start a transaction.
"""
return "BEGIN;"
def tablespace_sql(self, tablespace, inline=False):
"""
Returns the SQL that will be appended to tables or rows to define
a tablespace. Returns '' if the backend doesn't use tablespaces.
"""
return ''
def prep_for_like_query(self, x):
"""Prepares a value for use in a LIKE query."""
from django.utils.encoding import smart_unicode
return smart_unicode(x).replace("\\", "\\\\").replace("%", "\%").replace("_", "\_")
# Same as prep_for_like_query(), but called for "iexact" matches, which
# need not necessarily be implemented using "LIKE" in the backend.
prep_for_iexact_query = prep_for_like_query
def value_to_db_date(self, value):
"""
Transform a date value to an object compatible with what is expected
by the backend driver for date columns.
"""
if value is None:
return None
return datetime_safe.new_date(value).strftime('%Y-%m-%d')
def value_to_db_datetime(self, value):
"""
Transform a datetime value to an object compatible with what is expected
by the backend driver for datetime columns.
"""
if value is None:
return None
return unicode(value)
def value_to_db_time(self, value):
"""
Transform a datetime value to an object compatible with what is expected
by the backend driver for time columns.
"""
if value is None:
return None
return unicode(value)
def value_to_db_decimal(self, value, max_digits, decimal_places):
"""
Transform a decimal.Decimal value to an object compatible with what is
expected by the backend driver for decimal (numeric) columns.
"""
if value is None:
return None
return util.format_number(value, max_digits, decimal_places)
def year_lookup_bounds(self, value):
"""
Returns a two-elements list with the lower and upper bound to be used
with a BETWEEN operator to query a field value using a year lookup
`value` is an int, containing the looked-up year.
"""
first = '%s-01-01 00:00:00'
second = '%s-12-31 23:59:59.999999'
return [first % value, second % value]
def year_lookup_bounds_for_date_field(self, value):
"""
Returns a two-elements list with the lower and upper bound to be used
with a BETWEEN operator to query a DateField value using a year lookup
`value` is an int, containing the looked-up year.
By default, it just calls `self.year_lookup_bounds`. Some backends need
this hook because on their DB date fields can't be compared to values
which include a time part.
"""
return self.year_lookup_bounds(value)
class BaseDatabaseIntrospection(object):
"""
This class encapsulates all backend-specific introspection utilities
"""
data_types_reverse = {}
def __init__(self, connection):
self.connection = connection
def table_name_converter(self, name):
"""Apply a conversion to the name for the purposes of comparison.
The default table name converter is for case sensitive comparison.
"""
return name
def table_names(self):
"Returns a list of names of all tables that exist in the database."
cursor = self.connection.cursor()
return self.get_table_list(cursor)
def django_table_names(self, only_existing=False):
"""
Returns a list of all table names that have associated Django models and
are in INSTALLED_APPS.
If only_existing is True, the resulting list will only include the tables
that actually exist in the database.
"""
from django.db import models
tables = set()
for app in models.get_apps():
for model in models.get_models(app):
tables.add(model._meta.db_table)
tables.update([f.m2m_db_table() for f in model._meta.local_many_to_many])
if only_existing:
tables = [t for t in tables if t in self.table_names()]
return tables
def installed_models(self, tables):
"Returns a set of all models represented by the provided list of table names."
from django.db import models
all_models = []
for app in models.get_apps():
for model in models.get_models(app):
all_models.append(model)
return set([m for m in all_models
if self.table_name_converter(m._meta.db_table) in map(self.table_name_converter, tables)
])
def sequence_list(self):
"Returns a list of information about all DB sequences for all models in all apps."
from django.db import models
apps = models.get_apps()
sequence_list = []
for app in apps:
for model in models.get_models(app):
for f in model._meta.local_fields:
if isinstance(f, models.AutoField):
sequence_list.append({'table': model._meta.db_table, 'column': f.column})
break # Only one AutoField is allowed per model, so don't bother continuing.
for f in model._meta.local_many_to_many:
sequence_list.append({'table': f.m2m_db_table(), 'column': None})
return sequence_list
class BaseDatabaseClient(object):
"""
This class encapsulates all backend-specific methods for opening a
client shell.
"""
# This should be a string representing the name of the executable
# (e.g., "psql"). Subclasses must override this.
executable_name = None
def runshell(self):
raise NotImplementedError()
class BaseDatabaseValidation(object):
"""
This class encapsualtes all backend-specific model validation.
"""
def validate_field(self, errors, opts, f):
"By default, there is no backend-specific validation"
pass