[db engine] Add support for Elasticsearch (#8441)

* [db engine] Add support for Elasticsearch

superset/db_engine_specs/elasticsearch.py

@@ -0,0 +1,47 @@
+# 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.
+# pylint: disable=C,R,W
+from datetime import datetime
+from typing import Dict
+
+from superset.db_engine_specs.base import BaseEngineSpec
+
+
+class ElasticSearchEngineSpec(BaseEngineSpec):
+    engine = "elasticsearch"
+    time_groupby_inline = True
+    time_secondary_columns = True
+    allows_joins = False
+    allows_subqueries = True
+
+    _time_grain_functions = {
+        None: "{col}",
+        "PT1S": "HISTOGRAM({col}, INTERVAL 1 SECOND)",
+        "PT1M": "HISTOGRAM({col}, INTERVAL 1 MINUTE)",
+        "PT1H": "HISTOGRAM({col}, INTERVAL 1 HOUR)",
+        "P1D": "HISTOGRAM({col}, INTERVAL 1 DAY)",
+        "P1M": "HISTOGRAM({col}, INTERVAL 1 MONTH)",
+        "P1Y": "HISTOGRAM({col}, INTERVAL 1 YEAR)",
+    }
+
+    type_code_map: Dict[int, str] = {}  # loaded from get_datatype only if needed
+
+    @classmethod
+    def convert_dttm(cls, target_type: str, dttm: datetime) -> str:
+        if target_type.upper() in ("DATETIME", "DATE"):
+            return f"'{dttm.isoformat()}'"
+        return f"'{dttm.strftime('%Y-%m-%d %H:%M:%S')}'"