Commit 8c2db4ab authored by Russell Keith-Magee's avatar Russell Keith-Magee
Browse files

Fixed #10906 -- Added a check for PostgreSQL pre 8.2 when using... 

Fixed #10906 -- Added a check for PostgreSQL pre 8.2 when using StdDev/Variance aggregates. Thanks to Richard Davies for the report and patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@10731 bcc190cf-cafb-0310-a4f2-bffc1f526a37
parent b97178f7

django/db/backends/postgresql/operations.py

+8 −1
Original line number Diff line number Diff line
@@ -146,11 +146,18 @@ class DatabaseOperations(BaseDatabaseOperations): 
    def check_aggregate_support(self, aggregate):

        """Check that the backend fully supports the provided aggregate.



        The population and sample statistics (STDDEV_POP, STDDEV_SAMP,

        VAR_POP, VAR_SAMP) were first implemented in Postgres 8.2.



        The implementation of population statistics (STDDEV_POP and VAR_POP)

        under Postgres 8.2 - 8.2.4 is known to be faulty. Raise

        NotImplementedError if this is the database in use.

        """

        if aggregate.sql_function == 'STDDEV_POP' or aggregate.sql_function == 'VAR_POP':

        if aggregate.sql_function in ('STDDEV_POP', 'STDDEV_SAMP', 'VAR_POP', 'VAR_SAMP'):

            if self.postgres_version[0:2] < [8,2]:

                raise NotImplementedError('PostgreSQL does not support %s prior to version 8.2. Please upgrade your version of PostgreSQL.' % aggregate.sql_function)



        if aggregate.sql_function in ('STDDEV_POP', 'VAR_POP'):

            if self.postgres_version[0:2] == [8,2]:

                if self.postgres_version[2] is None or self.postgres_version[2] <= 4:

                    raise NotImplementedError('PostgreSQL 8.2 to 8.2.4 is known to have a faulty implementation of %s. Please upgrade your version of PostgreSQL.' % aggregate.sql_function)

tests/regressiontests/aggregation_regress/models.py

+20 −4
Original line number Diff line number Diff line 
# coding: utf-8

import pickle



from django.db import models

from django.db import connection, models

from django.conf import settings



try:
@@ -321,10 +321,26 @@ FieldError: Cannot compute Avg('mean_age'): 'mean_age' is an aggregate 
"""

}



if settings.DATABASE_ENGINE != 'sqlite3':

    __test__['API_TESTS'] += """

# Stddev and Variance are not guaranteed to be available for SQLite.

def run_stddev_tests():

    """Check to see if StdDev/Variance tests should be run.



    Stddev and Variance are not guaranteed to be available for SQLite, and

    are not available for PostgreSQL before 8.2.

    """

    if settings.DATABASE_ENGINE == 'sqlite3':

        return False



    class StdDevPop(object):

        sql_function = 'STDDEV_POP'



    try:

        connection.ops.check_aggregate_support(StdDevPop())

    except:

        return False

    return True



if run_stddev_tests():

    __test__['API_TESTS'] += """

>>> Book.objects.aggregate(StdDev('pages'))

{'pages__stddev': 311.46...}