refactor(mssql): port to sqlglot

.github/workflows/ibis-backends.yml

@@ -133,16 +133,16 @@ jobs:
             sys-deps:
               - cmake
               - ninja-build
-          # - name: mssql
-          #   title: MS SQL Server
-          #   extras:
-          #     - mssql
-          #   services:
-          #     - mssql
-          #   sys-deps:
-          #     - freetds-dev
-          #     - unixodbc-dev
-          #     - tdsodbc
+          - name: mssql
+            title: MS SQL Server
+            extras:
+              - mssql
+            services:
+              - mssql
+            sys-deps:
+              - freetds-dev
+              - unixodbc-dev
+              - tdsodbc
           - name: trino
             title: Trino
             extras:
@@ -237,18 +237,18 @@ jobs:
               sys-deps:
                 - cmake
                 - ninja-build
-          # - os: windows-latest
-          #   backend:
-          #     name: mssql
-          #     title: MS SQL Server
-          #     extras:
-          #       - mssql
-          #     services:
-          #       - mssql
-          #     sys-deps:
-          #       - freetds-dev
-          #       - unixodbc-dev
-          #       - tdsodbc
+          - os: windows-latest
+            backend:
+              name: mssql
+              title: MS SQL Server
+              extras:
+                - mssql
+              services:
+                - mssql
+              sys-deps:
+                - freetds-dev
+                - unixodbc-dev
+                - tdsodbc
           - os: windows-latest
             backend:
               name: trino

ibis/backends/base/sqlglot/__init__.py

@@ -16,6 +16,7 @@
 if TYPE_CHECKING:
     from collections.abc import Iterable, Iterator, Mapping
 
+    import pandas as pd
     import pyarrow as pa
 
     import ibis.expr.datatypes as dt
@@ -28,14 +29,36 @@ class SQLGlotBackend(BaseBackend):
     compiler: ClassVar[SQLGlotCompiler]
     name: ClassVar[str]
 
+    @property
+    def _sqlglot_dialect(self) -> str:
+        return self.compiler.dialect
+
     @classmethod
     def has_operation(cls, operation: type[ops.Value]) -> bool:
         # singledispatchmethod overrides `__get__` so we can't directly access
         # the dispatcher
         dispatcher = cls.compiler.visit_node.register.__self__.dispatcher
         return dispatcher.dispatch(operation) is not dispatcher.dispatch(object)
 
-    # TODO(kszucs): get_schema() is not registered as an abstract method
+    def _fetch_from_cursor(self, cursor, schema: sch.Schema) -> pd.DataFrame:
+        import pandas as pd
+
+        from ibis.formats.pandas import PandasData
+
+        try:
+            df = pd.DataFrame.from_records(
+                cursor, columns=schema.names, coerce_float=True
+            )
+        except Exception:
+            # clean up the cursor if we fail to create the DataFrame
+            #
+            # in the sqlite case failing to close the cursor results in
+            # artificially locked tables
+            cursor.close()
+            raise
+        df = PandasData.convert_table(df, schema)
+        return df
+
     def table(
         self, name: str, schema: str | None = None, database: str | None = None
     ) -> ir.Table:

ibis/backends/base/sqlglot/datatypes.py

@@ -837,3 +837,56 @@ def _from_sqlglot_MAP(cls, key: sge.DataType, value: sge.DataType) -> NoReturn:
     @classmethod
     def _from_sqlglot_STRUCT(cls, *cols: sge.ColumnDef) -> NoReturn:
         raise com.UnsupportedBackendType("Structs not supported in Exasol")
+
+
+class MSSQLType(SqlglotType):
+    dialect = "tsql"
+
+    @classmethod
+    def _from_sqlglot_BIT(cls):
+        return dt.Boolean(nullable=cls.default_nullable)
+
+    @classmethod
+    def _from_sqlglot_IMAGE(cls):
+        return dt.Binary(nullable=cls.default_nullable)
+
+    @classmethod
+    def _from_sqlglot_DATETIME(cls, n=None):
+        return dt.Timestamp(
+            scale=n if n is None else int(n.this.this), nullable=cls.default_nullable
+        )
+
+    @classmethod
+    def _from_sqlglot_TIMESTAMP(cls):
+        return dt.Binary(nullable=False)
+
+    @classmethod
+    def _from_ibis_String(cls, dtype: dt.String) -> sge.DataType:
+        return sge.DataType(
+            this=typecode.VARCHAR,
+            expressions=[sge.DataTypeParam(this=sge.Var(this="max"))],
+        )
+
+    @classmethod
+    def _from_ibis_Array(cls, dtype: dt.String) -> sge.DataType:
+        raise com.UnsupportedBackendType("SQL Server does not support arrays")
+
+    @classmethod
+    def _from_ibis_Map(cls, dtype: dt.String) -> sge.DataType:
+        raise com.UnsupportedBackendType("SQL Server does not support ")
+
+    @classmethod
+    def _from_ibis_Struct(cls, dtype: dt.String) -> sge.DataType:
+        raise com.UnsupportedBackendType("SQL Server does not support structs")
+
+    @classmethod
+    def _from_sqlglot_ARRAY(cls) -> sge.DataType:
+        raise com.UnsupportedBackendType("SQL Server does not support arrays")
+
+    @classmethod
+    def _from_sqlglot_MAP(cls) -> sge.DataType:
+        raise com.UnsupportedBackendType("SQL Server does not support map")
+
+    @classmethod
+    def _from_sqlglot_STRUCT(cls) -> sge.DataType:
+        raise com.UnsupportedBackendType("SQL Server does not support structs")

ibis/backends/conftest.py

@@ -563,7 +563,7 @@ def ddl_con(ddl_backend):
     return ddl_backend.connection
 
 
-@pytest.fixture(params=_get_backends_to_test(keep=("mssql", "sqlite")), scope="session")
+@pytest.fixture(params=_get_backends_to_test(keep=("sqlite",)), scope="session")
 def alchemy_backend(request, data_dir, tmp_path_factory, worker_id):
     """Set up the SQLAlchemy-based backends."""
     return _setup_backend(request, data_dir, tmp_path_factory, worker_id)