ensure correct cast for floats vs. numeric; other fixes

Fixed regression caused by the fix for :ticket:`9618` where floating point
values would lose precision being inserted in bulk, using either the
psycopg2 or psycopg drivers.

Implemented the :class:`_sqltypes.Double` type for SQL Server, having it
resolve to ``REAL``, or :class:`_mssql.REAL`, at DDL rendering time.

Fixed issue in Oracle dialects where ``Decimal`` returning types such as
:class:`_sqltypes.Numeric` would return floating point values, rather than
``Decimal`` objects, when these columns were used in the
:meth:`_dml.Insert.returning` clause to return INSERTed values.

Fixes: #9701
Change-Id: I8865496a6ccac6d44c19d0ca2a642b63c6172da9

1 files changed, 5 insertions, 0 deletions

diff --git a/lib/sqlalchemy/dialects/postgresql/_psycopg_common.py b/lib/sqlalchemy/dialects/postgresql/_psycopg_common.py
index 739cbc5a9..b98518099 100644
--- a/lib/sqlalchemy/dialects/postgresql/_psycopg_common.py
+++ b/lib/sqlalchemy/dialects/postgresql/_psycopg_common.py
@@ -55,6 +55,10 @@ class _PsycopgNumeric(sqltypes.Numeric):
                 )
 
 
+class _PsycopgFloat(_PsycopgNumeric):
+    __visit_name__ = "float"
+
+
 class _PsycopgHStore(HSTORE):
     def bind_processor(self, dialect):
         if dialect._has_native_hstore:
@@ -104,6 +108,7 @@ class _PGDialect_common_psycopg(PGDialect):
         PGDialect.colspecs,
         {
             sqltypes.Numeric: _PsycopgNumeric,
+            sqltypes.Float: _PsycopgFloat,
             HSTORE: _PsycopgHStore,
             sqltypes.ARRAY: _PsycopgARRAY,
             INT2VECTOR: _PsycopgINT2VECTOR,