Ticket #10906: 10906-r10633-detect-early-postgresql.diff

django/db/backends/postgresql/operations.py

@@ -152 +152 @@
     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 == 'STDDEV_SAMP' or aggregate.sql_function == 'VAR_POP' or aggregate.sql_function == 'VAR_SAMP':
+            if self.postgres_version[0] < 8 or (self.postgres_version[0] == 8 and self.postgres_version[1] < 2):
+                raise NotImplementedError('PostgreSQL does not support %s until version 8.2. Please upgrade your version of PostgreSQL.' % aggregate.sql_function)
+
         if aggregate.sql_function == 'STDDEV_POP' or aggregate.sql_function == 'VAR_POP':
             if self.postgres_version[0] == 8 and self.postgres_version[1] == 2 and 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

@@ -1 +1 @@
 # coding: utf-8
 import pickle
 
-from django.db import models
+from django.db import connection, models
 from django.conf import settings
 
 try:
@@ -321 +321 @@
 """
 }
 
-if settings.DATABASE_ENGINE != 'sqlite3':
+if not (settings.DATABASE_ENGINE == 'sqlite3' or
+        ((settings.DATABASE_ENGINE == 'postgresql' or settings.DATABASE_ENGINE == 'postgresql_psycopg2') and
+         (connection.ops.postgres_version[0] < 8 or (connection.ops.postgres_version[0] == 8 and connection.ops.postgres_version[1] < 2)))):
     __test__['API_TESTS'] += """
-# Stddev and Variance are not guaranteed to be available for SQLite.
+# Stddev and Variance are not guaranteed to be available for SQLite or PostgreSQL before 8.2.
 
 >>> Book.objects.aggregate(StdDev('pages'))
 {'pages__stddev': 311.46...}