Commit b3b71a09 authored by Malcolm Tredinnick's avatar Malcolm Tredinnick
Browse files

Fixed #7560 -- Moved a lot of the value conversion preparation for 

loading/saving interactions with the databases into django.db.backend. This
helps external db backend writers and removes a bunch of database-specific
if-tests in django.db.models.fields.

Great work from Leo Soto.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@8131 bcc190cf-cafb-0310-a4f2-bffc1f526a37
parent 7bc728c8

django/db/backends/__init__.py

+66 −4
Original line number Diff line number Diff line
@@ -5,6 +5,9 @@ except ImportError: 
    # Import copy of _thread_local.py from Python 2.4

    from django.utils._threading_local import local



from django.db.backends import util

from django.utils import datetime_safe



class BaseDatabaseWrapper(local):

    """

    Represents a database connection.
@@ -36,12 +39,13 @@ class BaseDatabaseWrapper(local): 
        return cursor



    def make_debug_cursor(self, cursor):

        from django.db.backends import util

        return util.CursorDebugWrapper(cursor, self)



class BaseDatabaseFeatures(object):

    allows_group_by_ordinal = True

    inline_fk_references = True

    # True if django.db.backend.utils.typecast_timestamp is used on values

    # returned from dates() calls.

    needs_datetime_string_cast = True

    supports_constraints = True

    supports_tablespaces = False
@@ -49,10 +53,7 @@ class BaseDatabaseFeatures(object): 
    uses_custom_query_class = False

    empty_fetchmany_value = []

    update_can_self_select = True

    supports_usecs = True

    time_field_needs_date = False

    interprets_empty_strings_as_nulls = False

    date_field_supports_time_value = True

    can_use_chunked_reads = True



class BaseDatabaseOperations(object):
@@ -263,3 +264,64 @@ class BaseDatabaseOperations(object): 
        """Prepares a value for use in a LIKE query."""

        from django.utils.encoding import smart_unicode

        return smart_unicode(x).replace("\\", "\\\\").replace("%", "\%").replace("_", "\_")



    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 date 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 date 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)

django/db/backends/mysql/base.py

+18 −1
Original line number Diff line number Diff line
@@ -63,7 +63,6 @@ class DatabaseFeatures(BaseDatabaseFeatures): 
    inline_fk_references = False

    empty_fetchmany_value = ()

    update_can_self_select = False

    supports_usecs = False



class DatabaseOperations(BaseDatabaseOperations):

    def date_extract_sql(self, lookup_type, field_name):
@@ -124,6 +123,24 @@ class DatabaseOperations(BaseDatabaseOperations): 
        else:

            return []



    def value_to_db_datetime(self, value):

        # MySQL doesn't support microseconds

        if value is None:

            return None

        return unicode(value.replace(microsecond=0))



    def value_to_db_time(self, value):

        # MySQL doesn't support microseconds

        if value is None:

            return None

        return unicode(value.replace(microsecond=0))



    def year_lookup_bounds(self, value):

        # Again, no microseconds

        first = '%s-01-01 00:00:00'

        second = '%s-12-31 23:59:59.99'

        return [first % value, second % value]



class DatabaseWrapper(BaseDatabaseWrapper):

    features = DatabaseFeatures()

    ops = DatabaseOperations()

django/db/backends/oracle/base.py

+17 −2
Original line number Diff line number Diff line
@@ -5,6 +5,8 @@ Requires cx_Oracle: http://www.python.net/crew/atuining/cx_Oracle/ 
"""



import os

import datetime

import time



from django.db.backends import BaseDatabaseWrapper, BaseDatabaseFeatures, BaseDatabaseOperations, util

from django.db.backends.oracle import query
@@ -28,9 +30,7 @@ class DatabaseFeatures(BaseDatabaseFeatures): 
    supports_tablespaces = True

    uses_case_insensitive_names = True

    uses_custom_query_class = True

    time_field_needs_date = True

    interprets_empty_strings_as_nulls = True

    date_field_supports_time_value = False



class DatabaseOperations(BaseDatabaseOperations):

    def autoinc_sql(self, table, column):
@@ -180,6 +180,21 @@ class DatabaseOperations(BaseDatabaseOperations): 
    def tablespace_sql(self, tablespace, inline=False):

        return "%sTABLESPACE %s" % ((inline and "USING INDEX " or ""), self.quote_name(tablespace))



    def value_to_db_time(self, value):

        if value is None:

            return None

        if isinstance(value, basestring):

            return datetime.datetime(*(time.strptime(value, '%H:%M:%S')[:6]))

        return datetime.datetime(1900, 1, 1, value.hour, value.minute,

                                 value.second, value.microsecond)



    def year_lookup_bounds_for_date_field(self, value):

        first = '%s-01-01'

        second = '%s-12-31'

        return [first % value, second % value]







class DatabaseWrapper(BaseDatabaseWrapper):

    features = DatabaseFeatures()

    ops = DatabaseOperations()

django/db/backends/sqlite3/base.py

+7 −1
Original line number Diff line number Diff line
@@ -84,6 +84,12 @@ class DatabaseOperations(BaseDatabaseOperations): 
        # sql_flush() implementations). Just return SQL at this point

        return sql



    def year_lookup_bounds(self, value):

        first = '%s-01-01'

        second = '%s-12-31 23:59:59.999999'

        return [first % value, second % value]





class DatabaseWrapper(BaseDatabaseWrapper):

    features = DatabaseFeatures()

    ops = DatabaseOperations()
@@ -159,7 +165,7 @@ def _sqlite_extract(lookup_type, dt): 
        dt = util.typecast_timestamp(dt)

    except (ValueError, TypeError):

        return None

    return str(getattr(dt, lookup_type))

    return getattr(dt, lookup_type)



def _sqlite_date_trunc(lookup_type, dt):

    try:

django/db/backends/util.py

+7 −0
Original line number Diff line number Diff line
@@ -117,3 +117,10 @@ def truncate_name(name, length=None): 
    hash = md5.md5(name).hexdigest()[:4]



    return '%s%s' % (name[:length-4], hash)



def format_number(value, max_digits, decimal_places):

    """

    Formats a number into a string with the requisite number of digits and

    decimal places.

    """

    return u"%.*f" % (decimal_places, value)