refactor(oracle): port to sqlglot

.github/workflows/ibis-backends.yml

@@ -155,20 +155,20 @@ jobs:
               - druid
             services:
               - druid
-          # - name: oracle
-          #   title: Oracle
-          #   serial: true
-          #   extras:
-          #     - oracle
-          #   services:
-          #     - oracle
           - name: exasol
             title: Exasol
             serial: true
             extras:
               - exasol
             services:
               - exasol
+          - name: oracle
+            title: Oracle
+            serial: true
+            extras:
+              - oracle
+            services:
+              - oracle
           # - name: flink
           #   title: Flink
           #   serial: true
@@ -265,15 +265,15 @@ jobs:
                 - druid
               services:
                 - druid
-          # - os: windows-latest
-          #   backend:
-          #     name: oracle
-          #     title: Oracle
-          #     serial: true
-          #     extras:
-          #       - oracle
-          #     services:
-          #       - oracle
+          - os: windows-latest
+            backend:
+              name: oracle
+              title: Oracle
+              serial: true
+              extras:
+                - oracle
+              services:
+                - oracle
           # - os: windows-latest
           #   backend:
           #     name: flink

ibis/backends/base/sqlglot/datatypes.py

@@ -563,6 +563,29 @@
 class OracleType(SqlglotType):
     dialect = "oracle"
 
+    default_decimal_precision = 38
+    default_decimal_scale = 9
+
+    default_temporal_scale = 9
+
+    unknown_type_strings = FrozenDict({"raw": dt.binary})
+
+    @classmethod
+    def _from_sqlglot_FLOAT(cls) -> dt.Float64:
+        return dt.Float64(nullable=cls.default_nullable)
+
+    @classmethod
+    def _from_sqlglot_DECIMAL(cls, precision=None, scale=None) -> dt.Decimal:
+        if scale is None or int(scale.this.this) == 0:
+            return dt.Int64(nullable=cls.default_nullable)
+        else:
+            return super()._from_sqlglot_DECIMAL(precision, scale)
+
+    @classmethod
+    def _from_ibis_String(cls, dtype: dt.String) -> sge.DataType:
+        nullable = " NOT NULL" if not dtype.nullable else ""
+        return "VARCHAR2(4000)" + nullable
+
 
 class SnowflakeType(SqlglotType):
     dialect = "snowflake"

ibis/backends/conftest.py

@@ -549,10 +549,7 @@ def ddl_con(ddl_backend):
     return ddl_backend.connection
 
 
-@pytest.fixture(
-    params=_get_backends_to_test(keep=("mssql", "oracle", "sqlite")),
-    scope="session",
-)
+@pytest.fixture(params=_get_backends_to_test(keep=("mssql", "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)