Add support for DECFLOAT

.gitignore

@@ -102,7 +102,6 @@ generated_version.py
 # Editor specific
 .idea/
 .vscode/
-*.code-workspace
 
 # WhiteSource Scan
 wss-*agent.config

DESCRIPTION.md

@@ -9,6 +9,10 @@ Source code is also available at:
 # Unreleased Notes
 
 # Release Notes
+- v1.8.0(TBD)
+  - Add support for `DECFLOAT`
+  - BREAKING CHANGE: The minimum supported version for the `snowflake-python-connector` has been increased to v3.14.1
+
 - v1.7.6(July 10, 2025)
   - Fix get_multi_indexes issue, wrong assign of returned indexes when processing multiple indexes in a table
 

junit.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?><testsuites name="pytest tests"><testsuite name="pytest" errors="0" failures="1" skipped="0" tests="1" time="4.775" timestamp="2025-07-18T14:56:49.960659+00:00" hostname="V9P2792XJ5"><testcase classname="tests.E2E.test_select_decfloat_type" name="test_select_decfloat_native_connector" time="4.279"><failure message="AssertionError: Return type is &lt;class 'str'&gt; 3.16.0&#10;assert False&#10; +  where False = isinstance('123456789.12345678', Decimal)">tests/E2E/test_select_decfloat_type.py:39: in test_select_decfloat_native_connector
+    assert isinstance(ret[0], Decimal), f"Return type is {type(ret[0])} {snowflake.connector.__version__}"
+E   AssertionError: Return type is &lt;class 'str'&gt; 3.16.0
+E   assert False
+E    +  where False = isinstance('123456789.12345678', Decimal)</failure></testcase></testsuite></testsuites>

pyproject.toml

@@ -8,7 +8,7 @@ dynamic = ["version"]
 description = "Snowflake SQLAlchemy Dialect"
 readme = "README.md"
 license = "Apache-2.0"
-requires-python = ">=3.8"
+requires-python = ">=3.9"
 authors = [
   { name = "Snowflake Inc.", email = "[email protected]" },
 ]
@@ -25,7 +25,6 @@ classifiers = [
   "Operating System :: OS Independent",
   "Programming Language :: Python :: 3",
   "Programming Language :: Python :: 3 :: Only",
-  "Programming Language :: Python :: 3.8",
   "Programming Language :: Python :: 3.9",
   "Programming Language :: Python :: 3.10",
   "Programming Language :: Python :: 3.11",
@@ -38,7 +37,7 @@ classifiers = [
   "Topic :: Software Development :: Libraries :: Application Frameworks",
   "Topic :: Software Development :: Libraries :: Python Modules",
 ]
-dependencies = ["SQLAlchemy>=1.4.19", "snowflake-connector-python<4.0.0"]
+dependencies = ["SQLAlchemy>=1.4.19", "snowflake-connector-python>=3.14.1,<4.0.0"]
 
 [tool.hatch.version]
 path = "src/snowflake/sqlalchemy/version.py"
@@ -79,13 +78,13 @@ path = ".venv"
 type = "virtual"
 extra-dependencies = ["SQLAlchemy>=1.4.19,<2.1.0"]
 features = ["development", "pandas"]
-python = "3.8"
+python = "3.9"
 installer = "uv"
 
 [tool.hatch.envs.sa14]
 extra-dependencies = ["SQLAlchemy>=1.4.19,<2.0.0"]
 features = ["development", "pandas"]
-python = "3.8"
+python = "3.9"
 
 [tool.hatch.envs.sa14.scripts]
 test-dialect = "pytest --ignore_v20_test -ra -vvv --tb=short --cov snowflake.sqlalchemy --cov-append --junitxml ./junit.xml --ignore=tests/sqlalchemy_test_suite tests/"
@@ -105,7 +104,7 @@ gh-cache-sum = "python -VV | sha256sum | cut -d' ' -f1"
 check-import = "python -c 'import snowflake.sqlalchemy; print(snowflake.sqlalchemy.__version__)'"
 
 [[tool.hatch.envs.release.matrix]]
-python = ["3.8", "3.9", "3.10", "3.11", "3.12"]
+python = ["3.9", "3.10", "3.11", "3.12"]
 features = ["development", "pandas"]
 
 [tool.hatch.envs.release.scripts]

snowflake-sqlalchemy.code-workspace

@@ -0,0 +1,28 @@
+{
+	"folders": [
+		{
+			"path": "."
+		},
+	],
+	"settings": {
+			"python.defaultInterpreterPath": ".venv/bin/python",
+			"python.testing.unittestEnabled": false,
+			"python.testing.pytestEnabled": true,
+			"debugpy.debugJustMyCode": false,
+			"python.testing.pytestArgs": [
+			"tests",
+			"-ra",
+			"-vvv",
+			"--tb=short",
+			"--junitxml=./junit.xml",
+			"--ignore=tests/sqlalchemy_test_suite"
+		]
+		},
+	"extensions": {
+    "recommendations": [
+      "ms-python.python",
+      "ms-python.vscode-pylance",
+	  "ms-python.debugpy",
+    ]
+  }
+}

snyk/requirements.txt

@@ -1,2 +1,2 @@
 SQLAlchemy>=1.4.19
-snowflake-connector-python<4.0.0
+snowflake-connector-python>=3.14.1,<4.0.0

src/snowflake/sqlalchemy/__init__.py

@@ -46,6 +46,7 @@
     BYTEINT,
     CHARACTER,
     DEC,
+    DECFLOAT,
     DOUBLE,
     FIXED,
     GEOGRAPHY,
@@ -121,6 +122,7 @@
     "VARBINARY",
     "VARIANT",
     "MAP",
+    "DECFLOAT",
 )
 
 _custom_commands = (

src/snowflake/sqlalchemy/base.py

@@ -7,10 +7,11 @@
 import re
 import string
 import warnings
-from typing import List
+from typing import Any, List
 
 from sqlalchemy import exc as sa_exc
 from sqlalchemy import inspect, sql
+from sqlalchemy import types as sqltypes
 from sqlalchemy import util as sa_util
 from sqlalchemy.engine import default
 from sqlalchemy.orm import context
@@ -1181,6 +1182,12 @@ def visit_GEOGRAPHY(self, type_, **kw):
     def visit_GEOMETRY(self, type_, **kw):
         return "GEOMETRY"
 
+    def visit_DECFLOAT(self, type_: sqltypes.DECIMAL[Any], **kw: Any) -> str:
+        if type_.precision is None:
+            return "DECFLOAT"
+        else:
+            return f"DECFLOAT({type_.precision})"
+
 
 construct_arguments = [(Table, {"clusterby": None})]
 

src/snowflake/sqlalchemy/custom_types.py

@@ -115,6 +115,10 @@ class GEOMETRY(SnowflakeType):
     __visit_name__ = "GEOMETRY"
 
 
+class DECFLOAT(SnowflakeType, sqltypes.DECIMAL):
+    __visit_name__ = "DECFLOAT"
+
+
 class _CUSTOM_Date(SnowflakeType, sqltypes.Date):
     def literal_processor(self, dialect):
         def process(value):

src/snowflake/sqlalchemy/parser/custom_type_parser.py

@@ -25,6 +25,7 @@
 from ..custom_types import (
     _CUSTOM_DECIMAL,
     ARRAY,
+    DECFLOAT,
     DOUBLE,
     GEOGRAPHY,
     GEOMETRY,
@@ -47,6 +48,7 @@
     "DATETIME": DATETIME,
     "DEC": DECIMAL,
     "DECIMAL": DECIMAL,
+    "DECFLOAT": DECFLOAT,
     "DOUBLE": DOUBLE,
     "FIXED": DECIMAL,
     "FLOAT": FLOAT,  # Snowflake FLOAT datatype doesn't have parameters

tests/E2E/__snapshots__/test_select_decfloat_type.ambr

@@ -0,0 +1,21 @@
+# serializer version: 1
+# name: test_create_table_with_decfloat
+  '''
+
+  CREATE TABLE mock_table (
+  	id DECFLOAT(38)
+  )
+
+
+  '''
+# ---
+# name: test_create_table_with_decfloat_without_precision
+  '''
+
+  CREATE TABLE mock_table (
+  	id DECFLOAT
+  )
+
+
+  '''
+# ---

tests/E2E/test_select_decfloat_type.py

@@ -0,0 +1,29 @@
+#
+# Copyright (c) 2012-2023 Snowflake Computing Inc. All rights reserved.
+
+from decimal import Decimal
+
+from sqlalchemy import cast, func, literal, select
+
+from snowflake.sqlalchemy import DECFLOAT
+
+
+def test_select_decfloat(engine_testaccount):
+    select_stmt = select(cast(literal("123.45"), DECFLOAT))
+
+    with engine_testaccount.connect() as connection:
+        result = connection.execute(select_stmt)
+        value = result.scalar_one()
+
+        assert value == Decimal("123.45")
+
+
+def test_select_decfloat_sum(engine_testaccount):
+    expr = cast(literal("123.45"), DECFLOAT) + cast(literal("100.55"), DECFLOAT)
+    select_stmt = select(func.sum(expr))
+
+    with engine_testaccount.connect() as connection:
+        result = connection.execute(select_stmt)
+        value = result.scalar_one()
+
+        assert value == Decimal("224.00")

tests/__snapshots__/test_core.ambr

@@ -2,3 +2,23 @@
 # name: test_compile_table_with_cluster_by_with_expression
   'CREATE TABLE clustered_user (\t"Id" INTEGER NOT NULL AUTOINCREMENT, \tname VARCHAR, \tPRIMARY KEY ("Id")) CLUSTER BY ("Id", name, "Id" > 5)'
 # ---
+# name: test_create_table_with_decfloat
+  '''
+
+  CREATE TABLE mock_table (
+  	id DECFLOAT(38)
+  )
+
+
+  '''
+# ---
+# name: test_create_table_with_decfloat_without_precision
+  '''
+
+  CREATE TABLE mock_table (
+  	id DECFLOAT
+  )
+
+
+  '''
+# ---

tests/test_core.py

@@ -44,7 +44,7 @@
 import snowflake.connector.errors
 import snowflake.sqlalchemy.snowdialect
 from snowflake.connector import Error, ProgrammingError, connect
-from snowflake.sqlalchemy import URL, MergeInto, dialect
+from snowflake.sqlalchemy import DECFLOAT, URL, MergeInto, dialect, snowdialect
 from snowflake.sqlalchemy._constants import (
     APPLICATION_NAME,
     SNOWFLAKE_SQLALCHEMY_VERSION,
@@ -1806,6 +1806,40 @@ def test_normalize_and_denormalize_empty_string_column_name(engine_testaccount):
         )
 
 
+def test_create_table_with_decfloat_without_precision(snapshot):
+    metadata = MetaData()
+
+    mock_table = Table(
+        "mock_table",
+        metadata,
+        Column("id", DECFLOAT),
+    )
+
+    compiled_sql = str(CreateTable(mock_table).compile(dialect=snowdialect.dialect()))
+
+    column = mock_table.c.id
+    assert isinstance(column.type, DECFLOAT)
+    assert column.type.precision is None
+    assert compiled_sql == snapshot
+
+
+def test_create_table_with_decfloat(snapshot):
+    metadata = MetaData()
+
+    mock_table = Table(
+        "mock_table",
+        metadata,
+        Column("id", DECFLOAT(38)),
+    )
+
+    compiled_sql = str(CreateTable(mock_table).compile(dialect=snowdialect.dialect()))
+
+    column = mock_table.c.id
+    assert isinstance(column.type, DECFLOAT)
+    assert column.type.precision == 38
+    assert compiled_sql == snapshot
+
+
 def test_snowflake_sqlalchemy_as_valid_client_type():
     engine = create_engine(
         URL(**CONNECTION_PARAMETERS),

tests/test_unit_structured_types.py

@@ -33,6 +33,8 @@ def test_extract_parameters():
         ("DATETIME(3)", "DATETIME"),
         ("DECIMAL(10, 2)", "DECIMAL(10, 2)"),
         ("DEC(10, 2)", "DECIMAL(10, 2)"),
+        ("DECFLOAT(38)", "DECFLOAT(38)"),
+        ("DECFLOAT", "DECFLOAT"),
         ("DOUBLE", "FLOAT"),
         ("FLOAT", "FLOAT"),
         ("FIXED(10, 2)", "DECIMAL(10, 2)"),