Merge branch 'main' into jcieslak/add-query-tag-support

# Conflicts:
#	DESCRIPTION.md
#	pyproject.toml

Author: sfc-gh-jcieslak

DESCRIPTION.md

@@ -13,6 +13,15 @@ Source code is also available at:
 - Add server_version_info support
 - Add support for `ILIKE` in queries
 - Fix `SYSDATE()` rendering
+- Fix and improve schema reflection (SNOW-593204, SNOW-2331576, SNOW-2852779)
+  - Fix crash when reflecting without specifying a schema, caused by `None` arguments in internal schema resolution ([#623](https://github.com/snowflakedb/snowflake-sqlalchemy/issues/623)).
+  - Fix crash when `SHOW TABLES` returns empty string table names, causing `IndexError` during reflection ([#296](https://github.com/snowflakedb/snowflake-sqlalchemy/issues/296)).
+  - Fix incomplete identity column reflection metadata, now includes all fields required by SQLAlchemy 2.0+ (`always`, `cycle`, `order`, etc.).
+  - Introduce shared helper for fully-qualified schema name resolution, replacing inconsistent ad-hoc patterns across reflection methods.
+  - Refactor column reflection internals into dedicated helpers to reduce complexity without changing behavior.
+  - Add `pytest-xdist` parallel test support via per-worker schema provisioning hooks.
+- Bump `pandas` lower bound in `sa14` test environment from `<2.1` to `>=2.1.1,<2.2` to ensure pre-built wheels are available for Python 3.12
+- Fix SQLAlchemy version parsing (SNOW-3066571)
 - Document support for session parameters (like [QUERY_TAG](https://docs.snowflake.com/en/sql-reference/parameters#query-tag)), references: [#644](https://github.com/snowflakedb/snowflake-sqlalchemy/issues/495)
 
 # Release Notes

ci/test_linux.sh

@@ -7,6 +7,8 @@
 #   - This is the script that test_docker.sh runs inside of the docker container
 
 PYTHON_VERSIONS="${1:-3.8 3.9 3.10 3.11 3.12 3.13 3.14}"
+# Python versions where pyarrow (required by pandas extra) is not available
+PANDAS_SKIP_VERSIONS="3.14"
 THIS_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 SQLALCHEMY_DIR="$(dirname "${THIS_DIR}")"
 
@@ -19,7 +21,12 @@ for PYTHON_VERSION in ${PYTHON_VERSIONS}; do
   echo "[Info] Testing with ${PYTHON_VERSION}"
   SHORT_VERSION=$(python3 -c "print('${PYTHON_VERSION}'.replace('.', ''))")
   SQLALCHEMY_WHL=$(ls $SQLALCHEMY_DIR/dist/snowflake_sqlalchemy-*-py3-none-any.whl | sort -r | head -n 1)
-  TEST_ENVLIST=fix_lint,py${SHORT_VERSION}-ci,py${SHORT_VERSION}-coverage,py${SHORT_VERSION}-pandas-ci,py${SHORT_VERSION}-pandas-coverage
+  TEST_ENVLIST=fix_lint,py${SHORT_VERSION}-ci
+  if [[ ! " ${PANDAS_SKIP_VERSIONS} " =~ " ${PYTHON_VERSION} " ]]; then
+    TEST_ENVLIST="${TEST_ENVLIST},py${SHORT_VERSION}-pandas-ci"
+  else
+    echo "[Info] Skipping pandas tests for Python ${PYTHON_VERSION} (pyarrow not available)"
+  fi
   echo "[Info] Running tox for ${TEST_ENVLIST}"
-  python3 -m tox -e ${TEST_ENVLIST} --installpkg ${SQLALCHEMY_WHL}
+  python3 -m tox -p auto -e ${TEST_ENVLIST} --installpkg ${SQLALCHEMY_WHL}
 done

pyproject.toml

@@ -55,7 +55,6 @@ development = [
   "pytest-xdist",
   "pytz",
   "numpy",
-  "mock",
   "syrupy",
 ]
 pandas = ["snowflake-connector-python[pandas]"]
@@ -85,7 +84,11 @@ installer = "uv"
 [tool.hatch.envs.sa14]
 installer = "uv"
 builder = true
-extra-dependencies = ["SQLAlchemy>=1.4.19,<2.0.0", "pandas>=2.1.1,<2.2", "numpy<2"]
+extra-dependencies = [
+  "SQLAlchemy>=1.4.19,<2.0.0",
+  "pandas>=2.1.1,<2.2",
+  "numpy<2",
+]
 features = ["development", "pandas"]
 python = "3.12"
 
@@ -142,4 +145,5 @@ markers = [
   "external: tests that could but should only run on our external CI",
   "feature_max_lob_size: tests that could but should only run on our external CI",
   "feature_v20: tests that could but should only run on SqlAlchemy v20",
+  "mypy: typing tests",
 ]

src/snowflake/sqlalchemy/compat.py

@@ -11,7 +11,7 @@
 string_types = (str,)
 returns_unicode = util.symbol("RETURNS_UNICODE")
 
-IS_VERSION_20 = tuple(int(v) for v in SA_VERSION.split(".")) >= (2, 0, 0)
+IS_VERSION_20 = tuple(int(v) for v in SA_VERSION.split(".")[:2]) >= (2, 0)
 
 
 def args_reducer(positions_to_drop: tuple):

src/snowflake/sqlalchemy/provision.py

@@ -1,7 +1,32 @@
 #
 # Copyright (c) 2012-2023 Snowflake Computing Inc. All rights reserved.
 #
-from sqlalchemy.testing.provision import set_default_schema_on_connection
+from sqlalchemy.testing.provision import (
+    create_db,
+    drop_db,
+    set_default_schema_on_connection,
+)
+
+
+@create_db.for_db("snowflake")
+def _snowflake_create_db(cfg, eng, ident):
+    """Create a schema for the xdist worker.
+
+    For Snowflake, we create schemas instead of databases since:
+    - Creating databases requires admin privileges
+    - Schema-level isolation is sufficient for test isolation
+    - The schema name becomes the 'ident' (e.g., test_schema_gw0)
+    """
+    with eng.begin() as conn:
+        # Create schema if it does not already exist
+        conn.exec_driver_sql(f"CREATE SCHEMA IF NOT EXISTS {ident}")
+
+
+@drop_db.for_db("snowflake")
+def _snowflake_drop_db(cfg, eng, ident):
+    """Drop the schema created for the xdist worker."""
+    with eng.begin() as conn:
+        conn.exec_driver_sql(f"DROP SCHEMA IF EXISTS {ident}")
 
 
 # This is only for test purpose required by Requirement "default_schema_name_switch"