Added engine spec for Virtuoso DBMS

superset/db_engine_specs/virtuoso.py

@@ -0,0 +1,95 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+from datetime import datetime
+from typing import Any, Optional
+
+from sqlalchemy import types
+
+from superset.constants import TimeGrain
+from superset.db_engine_specs.base import BaseEngineSpec, LimitMethod
+
+
+class VirtuosoEngineSpec(BaseEngineSpec):
+    """Engine for Virtuoso"""
+
+    engine = "virtuoso"
+    engine_name = "Virtuoso"
+
+    sqlalchemy_uri_placeholder = (
+        "virtuoso+pyodbc://user:password@dsn"
+    )
+
+    # Virtuoso uses FIRST to limit: `SELECT FIRST 10 * FROM table`
+    limit_method = LimitMethod.FETCH_MANY
+    max_column_name_length = 100
+    # supports_catalog = True
+    disable_ssh_tunneling = True
+
+    _time_grain_expressions = {
+        None: "{col}",
+        TimeGrain.SECOND: (
+            "CAST(CAST({col} AS DATE) "
+            "|| ' ' "
+            "|| EXTRACT(HOUR FROM {col}) "
+            "|| ':' "
+            "|| EXTRACT(MINUTE FROM {col}) "
+            "|| ':' "
+            "|| FLOOR(EXTRACT(SECOND FROM {col})) AS TIMESTAMP)"
+        ),
+        TimeGrain.MINUTE: (
+            "CAST(CAST({col} AS DATE) "
+            "|| ' ' "
+            "|| EXTRACT(HOUR FROM {col}) "
+            "|| ':' "
+            "|| EXTRACT(MINUTE FROM {col}) "
+            "|| ':00' AS TIMESTAMP)"
+        ),
+        TimeGrain.HOUR: (
+            "CAST(CAST({col} AS DATE) "
+            "|| ' ' "
+            "|| EXTRACT(HOUR FROM {col}) "
+            "|| ':00:00' AS TIMESTAMP)"
+        ),
+        TimeGrain.DAY: "CAST({col} AS DATE)",
+        TimeGrain.MONTH: (
+            "CAST(EXTRACT(YEAR FROM {col}) "
+            "|| '-' "
+            "|| EXTRACT(MONTH FROM {col}) "
+            "|| '-01' AS DATE)"
+        ),
+        TimeGrain.YEAR: "CAST(EXTRACT(YEAR FROM {col}) || '-01-01' AS DATE)",
+    }
+
+    @classmethod
+    def epoch_to_dttm(cls) -> str:
+        return "DATEADD('second', {col}, stringdate('1970-01-01'))"
+
+    @classmethod
+    def convert_dttm(
+        cls, target_type: str, dttm: datetime, db_extra: Optional[dict[str, Any]] = None
+    ) -> Optional[str]:
+        sqla_type = cls.get_sqla_column_type(target_type)
+
+        if isinstance(sqla_type, types.Date):
+            return f"CAST('{dttm.date().isoformat()}' AS DATE)"
+        if isinstance(sqla_type, types.DateTime):
+            dttm_formatted = dttm.isoformat(sep=" ")
+            dttm_valid_precision = dttm_formatted[: len("YYYY-MM-DD HH:MM:SS.MMMM")]
+            return f"CAST('{dttm_valid_precision}' AS TIMESTAMP)"
+        if isinstance(sqla_type, types.Time):
+            return f"CAST('{dttm.time().isoformat()}' AS TIME)"
+        return None