- pg8000 + postgresql dialects now check for float/numeric return

types to more intelligently determine float() vs. Decimal(),
[ticket:1567]
- since result processing is a hot issue of late, the DBAPI type
returned from cursor.description is certainly useful in cases like
these to determine an efficient result processor.   There's likely
other result processors that can make use of it.  But, backwards
incompat change to result_processor().  Happy major version number..

1 files changed, 61 insertions, 0 deletions

diff --git a/test/dialect/test_postgresql.py b/test/dialect/test_postgresql.py
index aa2b99275..152ca40da 100644
--- a/test/dialect/test_postgresql.py
+++ b/test/dialect/test_postgresql.py
@@ -2,6 +2,7 @@
 from sqlalchemy.test.testing import eq_, assert_raises, assert_raises_message
 from sqlalchemy.test import  engines
 import datetime
+import decimal
 from sqlalchemy import *
 from sqlalchemy.orm import *
 from sqlalchemy import exc, schema, types
@@ -10,6 +11,7 @@ from sqlalchemy.engine.strategies import MockEngineStrategy
 from sqlalchemy.test import *
 from sqlalchemy.sql import table, column
 from sqlalchemy.test.testing import eq_
+from test.engine._base import TablesTest
 
 class SequenceTest(TestBase, AssertsCompiledSQL):
     def test_basic(self):
@@ -105,6 +107,65 @@ class CompileTest(TestBase, AssertsCompiledSQL):
                 "SELECT EXTRACT(%s FROM t.col1::timestamp) AS anon_1 "
                 "FROM t" % field)
 
+class FloatCoercionTest(TablesTest, AssertsExecutionResults):
+    __only_on__ = 'postgresql'
+    __dialect__ = postgresql.dialect()
+
+    @classmethod
+    def define_tables(cls, metadata):
+        data_table = Table('data_table', metadata,
+            Column('id', Integer, primary_key=True),
+            Column('data', Integer)
+        )
+
+    @classmethod
+    @testing.resolve_artifact_names
+    def insert_data(cls):
+        data_table.insert().execute(
+            {'data':3},
+            {'data':5},
+            {'data':7},
+            {'data':2},
+            {'data':15},
+            {'data':12},
+            {'data':6},
+            {'data':478},
+            {'data':52},
+            {'data':9},
+        )
+    
+    def _round(self, x):
+        if isinstance(x, float):
+            return round(x, 9)
+        elif isinstance(x, decimal.Decimal):
+            # really ?
+            x = x.shift(decimal.Decimal(9)).to_integral() / pow(10, 9)
+        return x
+    @testing.resolve_artifact_names
+    def test_float_coercion(self):
+        for type_, result in [
+            (Numeric, decimal.Decimal('140.381230939')),
+            (Float, 140.381230939),
+            (Float(asdecimal=True), decimal.Decimal('140.381230939')),
+            (Numeric(asdecimal=False), 140.381230939),
+        ]:
+            ret = testing.db.execute(
+                select([
+                    func.stddev_pop(data_table.c.data, type_=type_)
+                ])
+            ).scalar()
+            
+            eq_(self._round(ret), result)
+
+            ret = testing.db.execute(
+                select([
+                    cast(func.stddev_pop(data_table.c.data), type_)
+                ])
+            ).scalar()
+            eq_(self._round(ret), result)
+    
+    
+        
 class EnumTest(TestBase, AssertsExecutionResults, AssertsCompiledSQL):
     __only_on__ = 'postgresql'
     __dialect__ = postgresql.dialect()