feat(sqlserver)!: the catalogue as statements, and the extended-property family

.github/workflows/test.yml

@@ -60,7 +60,7 @@
     - name: Install activerecord and testsuite from PyPI
       run: |
         pip install "rhosocial-activerecord @ git+https://github.com/rhosocial/python-activerecord.git@release/v1.0.0.dev30"
-        pip install "rhosocial-activerecord-testsuite @ git+https://github.com/rhosocial/python-activerecord-testsuite.git@release/v1.0.0.dev17"
+        pip install "rhosocial-activerecord-testsuite @ git+https://github.com/rhosocial/python-activerecord-testsuite.git@fix/column-constraint-gates"
 
     - name: Create test database
       run: |
@@ -150,7 +150,7 @@
     - name: Install activerecord and testsuite from PyPI
       run: |
         pip install "rhosocial-activerecord @ git+https://github.com/rhosocial/python-activerecord.git@release/v1.0.0.dev30"
-        pip install "rhosocial-activerecord-testsuite @ git+https://github.com/rhosocial/python-activerecord-testsuite.git@release/v1.0.0.dev17"
+        pip install "rhosocial-activerecord-testsuite @ git+https://github.com/rhosocial/python-activerecord-testsuite.git@fix/column-constraint-gates"
 
     - name: Create test database
       run: |
@@ -240,7 +240,7 @@
     - name: Install activerecord and testsuite from PyPI
       run: |
         pip install "rhosocial-activerecord @ git+https://github.com/rhosocial/python-activerecord.git@release/v1.0.0.dev30"
-        pip install "rhosocial-activerecord-testsuite @ git+https://github.com/rhosocial/python-activerecord-testsuite.git@release/v1.0.0.dev17"
+        pip install "rhosocial-activerecord-testsuite @ git+https://github.com/rhosocial/python-activerecord-testsuite.git@fix/column-constraint-gates"
 
     - name: Create test database
       run: |
@@ -330,7 +330,7 @@
     - name: Install activerecord and testsuite from PyPI
       run: |
         pip install "rhosocial-activerecord @ git+https://github.com/rhosocial/python-activerecord.git@release/v1.0.0.dev30"
-        pip install "rhosocial-activerecord-testsuite @ git+https://github.com/rhosocial/python-activerecord-testsuite.git@release/v1.0.0.dev17"
+        pip install "rhosocial-activerecord-testsuite @ git+https://github.com/rhosocial/python-activerecord-testsuite.git@fix/column-constraint-gates"
 
     - name: Create test database
       run: |
@@ -420,7 +420,7 @@
     - name: Install activerecord and testsuite from PyPI
       run: |
         pip install "rhosocial-activerecord @ git+https://github.com/rhosocial/python-activerecord.git@release/v1.0.0.dev30"
-        pip install "rhosocial-activerecord-testsuite @ git+https://github.com/rhosocial/python-activerecord-testsuite.git@release/v1.0.0.dev17"
+        pip install "rhosocial-activerecord-testsuite @ git+https://github.com/rhosocial/python-activerecord-testsuite.git@fix/column-constraint-gates"
 
     - name: Create test database
       run: |
@@ -510,7 +510,7 @@
     - name: Install activerecord and testsuite from PyPI
       run: |
         pip install "rhosocial-activerecord @ git+https://github.com/rhosocial/python-activerecord.git@release/v1.0.0.dev30"
-        pip install "rhosocial-activerecord-testsuite @ git+https://github.com/rhosocial/python-activerecord-testsuite.git@release/v1.0.0.dev17"
+        pip install "rhosocial-activerecord-testsuite @ git+https://github.com/rhosocial/python-activerecord-testsuite.git@fix/column-constraint-gates"
 
     - name: Create test database
       run: |
@@ -601,7 +601,7 @@
     - name: Install activerecord and testsuite from PyPI
       run: |
         pip install "rhosocial-activerecord @ git+https://github.com/rhosocial/python-activerecord.git@release/v1.0.0.dev30"
-        pip install "rhosocial-activerecord-testsuite @ git+https://github.com/rhosocial/python-activerecord-testsuite.git@release/v1.0.0.dev17"
+        pip install "rhosocial-activerecord-testsuite @ git+https://github.com/rhosocial/python-activerecord-testsuite.git@fix/column-constraint-gates"
 
     - name: Create test database
       run: |
@@ -691,7 +691,7 @@
     - name: Install activerecord and testsuite from PyPI
       run: |
         pip install "rhosocial-activerecord @ git+https://github.com/rhosocial/python-activerecord.git@release/v1.0.0.dev30"
-        pip install "rhosocial-activerecord-testsuite @ git+https://github.com/rhosocial/python-activerecord-testsuite.git@release/v1.0.0.dev17"
+        pip install "rhosocial-activerecord-testsuite @ git+https://github.com/rhosocial/python-activerecord-testsuite.git@fix/column-constraint-gates"
 
     - name: Create test database
       run: |
@@ -790,7 +790,7 @@
     - name: Install activerecord and testsuite from PyPI
       run: |
         pip install "rhosocial-activerecord @ git+https://github.com/rhosocial/python-activerecord.git@release/v1.0.0.dev30"
-        pip install "rhosocial-activerecord-testsuite @ git+https://github.com/rhosocial/python-activerecord-testsuite.git@release/v1.0.0.dev17"
+        pip install "rhosocial-activerecord-testsuite @ git+https://github.com/rhosocial/python-activerecord-testsuite.git@fix/column-constraint-gates"
 
     - name: Create test database
       run: |

.gitignore

@@ -212,3 +212,8 @@ __marimo__/
 .claude/tmp/
 tests/config/
 test_connection.py
+# Worktrees for feature/* and fix/* branches. Never tracked: a `git add -A`
+# from the repo root would commit each branch's whole toolchain -- the venv, the
+# build directory and the test artifacts -- and the directory disappears when the
+# branch merges, so the history would keep a second copy of the source tree.
+.worktree/

README.md

@@ -46,11 +46,11 @@ from typing import ClassVar, Optional
 from rhosocial.activerecord.base import FieldProxy
 from rhosocial.activerecord.backend.impl.sqlserver.backend import SQLServerBackend
 from rhosocial.activerecord.backend.impl.sqlserver.config import SQLServerConnectionConfig
-from rhosocial.activerecord.backend.expression import CreateTableExpression
+from rhosocial.activerecord.backend.expression import CreateTableStatement
 from rhosocial.activerecord.backend.expression.statements import (
     ColumnConstraint,
-    ColumnConstraintType,
     ColumnDefinition,
+    ColumnPrimaryKeyConstraint,
 )
 from rhosocial.activerecord.backend.expression.types import IntegerType, VarCharType
 from rhosocial.activerecord.model import ActiveRecord
@@ -79,14 +79,16 @@ User.configure(
 )
 
 dialect = User.__backend__.dialect
-User.__backend__.execute(*CreateTableExpression(
+User.__backend__.execute(*CreateTableStatement(
     dialect,
     "users",
     columns=[
         ColumnDefinition(
             dialect, "id", IntegerType(dialect),
-            constraints=[ColumnConstraint(dialect, ColumnConstraintType.PRIMARY_KEY,
-                is_auto_increment=True)],
+            constraints=[ColumnConstraint(
+                dialect,
+                branch=ColumnPrimaryKeyConstraint(dialect, is_auto_increment=True),
+            )],
         ),
         ColumnDefinition(dialect, "name", VarCharType(dialect, 100)),
         ColumnDefinition(dialect, "email", VarCharType(dialect, 255)),
@@ -145,7 +147,7 @@ from rhosocial.activerecord.backend.impl.sqlserver.expression import (
     SQLServerCreateTableOptions,
 )
 
-CreateTableExpression(
+CreateTableStatement(
     dialect,
     "sessions",
     columns=[...],

changelog.d/9.added.md

@@ -0,0 +1,3 @@
+The extended-property family, asked by table name, plus table and column comments read from `MS_Description`; and `views NAME` on the introspect CLI, whose twelve types derive from `_TYPE_CAPABILITIES`.
+
+Add the SQL Server catalogue questions core has no shape for, on both introspector managers with identical signatures: ``list_schemas`` (``sys.schemas`` with the owning database principal resolved by ``principal_id``, not name), ``list_extended_properties`` (``sys.extended_properties`` -- ``MS_Description`` and friends -- for one catalogue object, optionally one column, with the ``sql_variant`` value cast off the type pyodbc cannot fetch), ``list_procedures`` and ``list_functions`` (``sys.objects`` types ``P``/``PC`` and ``FN``/``IF``/``TF``/``FS``/``FT``, one builder parameterized by the code set), and ``list_sequences`` (``sys.sequences`` with every ``sql_variant`` bound cast to text and parsed back into exact ``Decimal`` values rather than floats that would round a wide sequence's bounds). Each question is built from expression nodes and rendered by the dialect, carries its family name into its cache key so two families never answer each other, and reports a schema-free family as unknown rather than returning nothing.

changelog.d/9.changed.md

@@ -0,0 +1 @@
+A system table is not a base table; the backend-only catalogue questions are statement classes; and a `NAME` a type cannot use is an error (exit 2) instead of an ignored argument.

changelog.d/9.fixed.md

@@ -0,0 +1,3 @@
+A view's definition is read from `INFORMATION_SCHEMA.VIEWS` rather than left null, and a trigger reports the events that fire it and whether it is disabled. Two returns displaced by inserted switches were restored, and the expression matrix registers the new statement instead of skipping it.
+
+Fix the ``introspect`` subcommand calling introspector methods that exist nowhere in the backend. It asked ``get_tables``/``get_views``/``get_columns``/``get_indexes``/``get_foreign_keys``/``get_triggers``/``get_constraints``/``get_procedures``/``get_functions``/``get_sequences`` -- core spells those questions ``list_tables``/``list_views``/``list_columns`` and friends -- so every type failed against a live server while the old offline fakes answered the misspelled names happily. The type-to-method mapping now lives in one place (``_steps``) and is exercised twice: the offline dispatch test checks every advertised type against the real introspector classes with no fake in the way, and a live test runs the command itself against a SQL Server. ``table`` and ``database <name>`` now render through ``get_table_info``, whose single query already fills columns, indexes and foreign keys, replacing the three separate calls plus the iteration over every table that triggers used to need.

changelog.d/9.internal.md

@@ -0,0 +1 @@
+The catalogue questions moved to statement classes, the CLI tests follow the removed aggregate, and CI installs core from `release/v1.0.0.dev30` now that core #127 has merged.

pyproject.toml

@@ -62,6 +62,7 @@ dev = [
     "ruff>=0.1.0",
     "pre-commit>=3.0.0",
     "towncrier>=23.0.0",
+    "pytest-xdist>=3.0.0",
     "rhosocial-activerecord-testsuite",
 ]
 docs = [

pytest.ini

@@ -5,9 +5,18 @@ testpaths = tests
 python_files = test_*.py
 python_classes = Test*
 python_functions = test_*
-addopts = -v --tb=short -p rhosocial.activerecord.testsuite.conftest
+; pythonpath is what makes ``-p plugins.expression_xdist`` loadable: pytest
+; applies this ini value *before* it imports the -p plugins, and a plugin
+; imported by name has to be findable by name. It also means a plain ``pytest``
+; invocation works without PYTHONPATH=src:tests, which CI sets anyway.
+pythonpath = tests
+; plugins.expression_xdist is this repository's own: it makes the expression
+; area (feature/backend/expression) parallel by default, which the org test
+; rules ask for and a conftest cannot do because xdist reads the worker count
+; before any conftest loads. See tests/plugins/expression_xdist.py.
+addopts = -v --tb=short -p rhosocial.activerecord.testsuite.conftest -p plugins.expression_xdist
 filterwarnings =
     ignore::DeprecationWarning
 markers =
     requires_sqlserver: mark test as requiring SQL Server connection
-    slow: mark test as slow running
+    slow: mark test as slow running

src/rhosocial/activerecord/backend/impl/sqlserver/alter_table_modifier.py

@@ -30,11 +30,33 @@ def supports_add_column_if_not_exists(self) -> bool:
         return False
 
     def supports_drop_column_if_exists(self) -> bool:
-        """``DROP COLUMN IF EXISTS`` is supported since SQL Server 2016."""
+        """``DROP COLUMN IF EXISTS`` is supported since SQL Server 2016.
+
+        The "since 2016" floor comes from the official ``ALTER TABLE``
+        grammar page; the instance measured here is 2019 only
+        (``tests/config/sqlserver_scenarios.yaml``: ``sqlserver_2019``,
+        RTM-CU32-GDR 15.0.4465.1, Developer Edition).
+        """
         return True
 
     def supports_drop_constraint_if_exists(self) -> bool:
-        """``DROP CONSTRAINT IF EXISTS`` is supported since SQL Server 2016."""
+        """``DROP CONSTRAINT IF EXISTS`` is supported since SQL Server 2016.
+
+        Measured on 2019 (RTM-CU32-GDR, 15.0.4465.1)::
+
+            ALTER TABLE dbo.probe_t DROP CONSTRAINT IF EXISTS does_not_exist
+            -> accepted, silent no-op (no result set, no error)
+
+        so ``IF EXISTS`` is what makes dropping a constraint idempotent on
+        this backend — the plain form is *not* a no-op, it raises
+        ``'does_not_exist' is not a constraint. (3728)`` followed by
+        ``Could not drop constraint. See previous errors. (3727)``.
+        Catching that error pair instead of spelling ``IF EXISTS`` would also
+        break on MySQL, which has no ``DROP CONSTRAINT IF EXISTS`` at all.
+
+        The "since 2016" floor is from the official ``ALTER TABLE`` grammar
+        page; no pre-2019 instance was measured here.
+        """
         return True
 
     def format_add_column_action(self, action: Any) -> Tuple[str, tuple]:
@@ -112,10 +134,13 @@ def format_alter_column_type_action(self, action: Any) -> Tuple[str, tuple]:
         if data_type is None:
             raise ValueError("data type is required for ALTER COLUMN")
 
+        from rhosocial.activerecord.backend.expression.types import DataType
+
+        type_sql, _ = DataType.as_type(self, data_type).to_sql()
         parts = [
             "ALTER COLUMN",
             self.format_identifier(action.column_name),
-            str(data_type),
+            type_sql,
         ]
 
         collate = getattr(action, "collate", None)

src/rhosocial/activerecord/backend/impl/sqlserver/backend/async_backend.py

@@ -30,6 +30,12 @@
 from ..async_transaction import AsyncSQLServerTransactionManager
 from .backend import SQLServerUnicodeDialect
 from ..mixins import SQLServerBackendMixin
+from ..query_nodes import (
+    health_check_sql,
+    identity_columns_sql,
+    server_property_value_sql,
+    session_identity_sql,
+)
 
 try:
     import aioodbc
@@ -253,8 +259,9 @@ async def _get_cursor(self):
 
     async def _get_scope_identity_async(self) -> Optional[int]:
         """Get the identity value of the last INSERT via @@IDENTITY."""
+        sql, params = session_identity_sql(self.dialect)
         async with await self._get_cursor() as cursor:
-            await cursor.execute("SELECT @@IDENTITY")
+            await cursor.execute(sql, params)
             row = await cursor.fetchone()
         if row and row[0] is not None:
             return int(row[0])
@@ -273,13 +280,9 @@ async def _get_identity_columns_async(self, table_name: str) -> Set[str]:
             return self._identity_columns_cache[cache_key]
         columns: Set[str] = set()
         try:
+            sql, params = identity_columns_sql(self.dialect, table_name)
             async with await self._get_cursor() as cursor:
-                await cursor.execute(
-                    "SELECT c.name FROM sys.identity_columns c "
-                    "JOIN sys.tables t ON c.object_id = t.object_id "
-                    f"WHERE t.name = {self.dialect.p()} AND SCHEMA_NAME(t.schema_id) = 'dbo'",
-                    (table_name,),
-                )
+                await cursor.execute(sql, params)
                 for row in await cursor.fetchall():
                     columns.add(str(row[0]).lower())
         except Exception:
@@ -413,8 +416,8 @@ async def _execute_statement(
                     data = []
                     for row in rows:
                         row_dict = dict(zip(column_names, row))
-                        adapted_row = self._adapt_row_types(row_dict, adapters)
-                        final_row = self._remap_row_columns(adapted_row, mapping)
+                        adapted_row = self.adapt_row_types(row_dict, adapters)
+                        final_row = self.remap_row_columns(adapted_row, mapping)
                         data.append(final_row)
                 elif cursor.description:
                     # Also process result when cursor has data (e.g. OUTPUT clause)
@@ -426,8 +429,8 @@ async def _execute_statement(
                         data = []
                         for row in rows:
                             row_dict = dict(zip(column_names, row))
-                            adapted_row = self._adapt_row_types(row_dict, adapters)
-                            final_row = self._remap_row_columns(adapted_row, mapping)
+                            adapted_row = self.adapt_row_types(row_dict, adapters)
+                            final_row = self.remap_row_columns(adapted_row, mapping)
                             data.append(final_row)
                     except Exception:
                         data = None
@@ -500,8 +503,11 @@ async def get_server_version(self) -> Tuple[int, int, int]:
             await self.connect()
 
         try:
+            probe, probe_params = server_property_value_sql(
+                self.dialect, "ProductVersion"
+            )
             async with await self._get_cursor() as cursor:
-                await cursor.execute("SELECT SERVERPROPERTY('ProductVersion')")
+                await cursor.execute(probe, probe_params)
                 row = await cursor.fetchone()
 
                 if row:
@@ -536,8 +542,9 @@ async def ping(self, reconnect: bool = True) -> bool:
                     return True
                 return False
 
+            probe, probe_params = health_check_sql(self.dialect)
             async with await self._get_cursor() as cursor:
-                await cursor.execute("SELECT 1")
+                await cursor.execute(probe, probe_params)
                 await cursor.fetchone()
             return True
 

src/rhosocial/activerecord/backend/impl/sqlserver/backend/backend.py

@@ -32,6 +32,7 @@
 from ..dialect import SQLServerDialect
 from ..transaction import SQLServerTransactionManager
 from ..mixins import SQLServerBackendMixin, SQLServerConcurrencyMixin
+from ..query_nodes import health_check_sql, server_property_value_sql
 
 
 class SQLServerUnicodeDialect(SQLServerDialect):
@@ -289,8 +290,9 @@ def _get_cursor(self):
             self.connect()
 
         try:
+            probe, probe_params = health_check_sql(self.dialect)
             cursor = self._connection.cursor()
-            cursor.execute("SELECT 1")
+            cursor.execute(probe, probe_params)
             cursor.fetchone()
             cursor.close()
         except (PyODBCError, InterfaceError) as e:
@@ -460,8 +462,11 @@ def get_server_version(self) -> Tuple[int, int, int]:
 
         cursor = None
         try:
+            probe, probe_params = server_property_value_sql(
+                self.dialect, "ProductVersion"
+            )
             cursor = self._get_cursor()
-            cursor.execute("SELECT SERVERPROPERTY('ProductVersion')")
+            cursor.execute(probe, probe_params)
             version_str = cursor.fetchone()[0]
 
             parts = version_str.split('.')
@@ -497,8 +502,9 @@ def ping(self, reconnect: bool = True) -> bool:
                     return True
                 return False
 
+            probe, probe_params = health_check_sql(self.dialect)
             cursor = self._get_cursor()
-            cursor.execute("SELECT 1")
+            cursor.execute(probe, probe_params)
             cursor.fetchone()
             cursor.close()
             return True