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# 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=line-too-long
"""A collection of ORM sqlalchemy models for Superset"""
import enum
import json
import logging
import textwrap
from ast import literal_eval
from contextlib import closing, contextmanager
from copy import deepcopy
from datetime import datetime
from typing import Any, Callable, Dict, List, Optional, Set, Tuple, Type

import numpy
import pandas as pd
import sqlalchemy as sqla
from flask import g, request
from flask_appbuilder import Model
from sqlalchemy import (
    Boolean,
    Column,
    create_engine,
    DateTime,
    ForeignKey,
    Integer,
    MetaData,
    String,
    Table,
    Text,
)
from sqlalchemy.engine import Connection, Dialect, Engine
from sqlalchemy.engine.reflection import Inspector
from sqlalchemy.engine.url import URL
from sqlalchemy.exc import ArgumentError, NoSuchModuleError
from sqlalchemy.ext.hybrid import hybrid_property
from sqlalchemy.orm import relationship
from sqlalchemy.pool import NullPool
from sqlalchemy.schema import UniqueConstraint
from sqlalchemy.sql import expression, Select

from superset import app, db_engine_specs
from superset.constants import PASSWORD_MASK
from superset.databases.utils import make_url_safe
from superset.db_engine_specs.base import MetricType, TimeGrain
from superset.extensions import cache_manager, encrypted_field_factory, security_manager
from superset.models.helpers import AuditMixinNullable, ImportExportMixin
from superset.result_set import SupersetResultSet
from superset.utils import cache as cache_util, core as utils
from superset.utils.core import get_username
from superset.utils.memoized import memoized

config = app.config
custom_password_store = config["SQLALCHEMY_CUSTOM_PASSWORD_STORE"]
stats_logger = config["STATS_LOGGER"]
log_query = config["QUERY_LOGGER"]
metadata = Model.metadata  # pylint: disable=no-member
logger = logging.getLogger(__name__)

DB_CONNECTION_MUTATOR = config["DB_CONNECTION_MUTATOR"]


class Url(Model, AuditMixinNullable):
    """Used for the short url feature"""

    __tablename__ = "url"
    id = Column(Integer, primary_key=True)
    url = Column(Text)


class KeyValue(Model):  # pylint: disable=too-few-public-methods

    """Used for any type of key-value store"""

    __tablename__ = "keyvalue"
    id = Column(Integer, primary_key=True)
    value = Column(Text, nullable=False)


class CssTemplate(Model, AuditMixinNullable):
    """CSS templates for dashboards"""

    __tablename__ = "css_templates"
    id = Column(Integer, primary_key=True)
    template_name = Column(String(250))
    css = Column(Text, default="")


class ConfigurationMethod(str, enum.Enum):
    SQLALCHEMY_FORM = "sqlalchemy_form"
    DYNAMIC_FORM = "dynamic_form"


class Database(
    Model, AuditMixinNullable, ImportExportMixin
):  # pylint: disable=too-many-public-methods

    """An ORM object that stores Database related information"""

    __tablename__ = "dbs"
    type = "table"
    __table_args__ = (UniqueConstraint("database_name"),)

    id = Column(Integer, primary_key=True)
    verbose_name = Column(String(250), unique=True)
    # short unique name, used in permissions
    database_name = Column(String(250), unique=True, nullable=False)
    sqlalchemy_uri = Column(String(1024), nullable=False)
    password = Column(encrypted_field_factory.create(String(1024)))
    cache_timeout = Column(Integer)
    select_as_create_table_as = Column(Boolean, default=False)
    expose_in_sqllab = Column(Boolean, default=True)
    configuration_method = Column(
        String(255), server_default=ConfigurationMethod.SQLALCHEMY_FORM.value
    )
    allow_run_async = Column(Boolean, default=False)
    allow_file_upload = Column(Boolean, default=False)
    allow_ctas = Column(Boolean, default=False)
    allow_cvas = Column(Boolean, default=False)
    allow_dml = Column(Boolean, default=False)
    force_ctas_schema = Column(String(250))
    extra = Column(
        Text,
        default=textwrap.dedent(
            """\
    {
        "metadata_params": {},
        "engine_params": {},
        "metadata_cache_timeout": {},
        "schemas_allowed_for_file_upload": []
    }
    """
        ),
    )
    encrypted_extra = Column(encrypted_field_factory.create(Text), nullable=True)
    impersonate_user = Column(Boolean, default=False)
    server_cert = Column(encrypted_field_factory.create(Text), nullable=True)
    is_managed_externally = Column(Boolean, nullable=False, default=False)
    external_url = Column(Text, nullable=True)

    export_fields = [
        "database_name",
        "sqlalchemy_uri",
        "cache_timeout",
        "expose_in_sqllab",
        "allow_run_async",
        "allow_ctas",
        "allow_cvas",
        "allow_file_upload",
        "extra",
    ]
    extra_import_fields = [
        "password",
        "is_managed_externally",
        "external_url",
        "encrypted_extra",
    ]
    export_children = ["tables"]

    def __repr__(self) -> str:
        return self.name

    @property
    def name(self) -> str:
        return self.verbose_name if self.verbose_name else self.database_name

    @property
    def allows_subquery(self) -> bool:
        return self.db_engine_spec.allows_subqueries

    @property
    def function_names(self) -> List[str]:
        try:
            return self.db_engine_spec.get_function_names(self)
        except Exception as ex:  # pylint: disable=broad-except
            # function_names property is used in bulk APIs and should not hard crash
            # more info in: https://github.com/apache/superset/issues/9678
            logger.error(
                "Failed to fetch database function names with error: %s",
                str(ex),
                exc_info=True,
            )
        return []

    @property
    def allows_cost_estimate(self) -> bool:
        extra = self.get_extra() or {}
        cost_estimate_enabled: bool = extra.get("cost_estimate_enabled")  # type: ignore

        return (
            self.db_engine_spec.get_allow_cost_estimate(extra) and cost_estimate_enabled
        )

    @property
    def allows_virtual_table_explore(self) -> bool:
        extra = self.get_extra()

        return bool(extra.get("allows_virtual_table_explore", True))

    @property
    def explore_database_id(self) -> int:
        return self.get_extra().get("explore_database_id", self.id)

    @property
    def disable_data_preview(self) -> bool:
        # this will prevent any 'trash value' strings from going through
        if self.get_extra().get("disable_data_preview", False) is not True:
            return False
        return True

    @property
    def data(self) -> Dict[str, Any]:
        return {
            "id": self.id,
            "name": self.database_name,
            "backend": self.backend,
            "configuration_method": self.configuration_method,
            "allows_subquery": self.allows_subquery,
            "allows_cost_estimate": self.allows_cost_estimate,
            "allows_virtual_table_explore": self.allows_virtual_table_explore,
            "explore_database_id": self.explore_database_id,
            "parameters": self.parameters,
            "disable_data_preview": self.disable_data_preview,
            "parameters_schema": self.parameters_schema,
            "engine_information": self.engine_information,
        }

    @property
    def unique_name(self) -> str:
        return self.database_name

    @property
    def url_object(self) -> URL:
        return make_url_safe(self.sqlalchemy_uri_decrypted)

    @property
    def backend(self) -> str:
        return self.url_object.get_backend_name()

    @property
    def driver(self) -> str:
        return self.url_object.get_driver_name()

    @property
    def masked_encrypted_extra(self) -> Optional[str]:
        return self.db_engine_spec.mask_encrypted_extra(self.encrypted_extra)

    @property
    def parameters(self) -> Dict[str, Any]:
        # Database parameters are a dictionary of values that are used to make up
        # the sqlalchemy_uri
        # When returning the parameters we should use the masked SQLAlchemy URI and the
        # masked ``encrypted_extra`` to prevent exposing sensitive credentials.
        masked_uri = make_url_safe(self.sqlalchemy_uri)
        masked_encrypted_extra = self.masked_encrypted_extra
        encrypted_config = {}
        if masked_encrypted_extra is not None:
            try:
                encrypted_config = json.loads(masked_encrypted_extra)
            except (TypeError, json.JSONDecodeError):
                pass

        try:
            # pylint: disable=useless-suppression
            parameters = self.db_engine_spec.get_parameters_from_uri(  # type: ignore
                masked_uri,
                encrypted_extra=encrypted_config,
            )
        except Exception:  # pylint: disable=broad-except
            parameters = {}

        return parameters

    @property
    def parameters_schema(self) -> Dict[str, Any]:
        try:
            parameters_schema = self.db_engine_spec.parameters_json_schema()  # type: ignore
        except Exception:  # pylint: disable=broad-except
            parameters_schema = {}
        return parameters_schema

    @property
    def metadata_cache_timeout(self) -> Dict[str, Any]:
        return self.get_extra().get("metadata_cache_timeout", {})

    @property
    def schema_cache_enabled(self) -> bool:
        return "schema_cache_timeout" in self.metadata_cache_timeout

    @property
    def schema_cache_timeout(self) -> Optional[int]:
        return self.metadata_cache_timeout.get("schema_cache_timeout")

    @property
    def table_cache_enabled(self) -> bool:
        return "table_cache_timeout" in self.metadata_cache_timeout

    @property
    def table_cache_timeout(self) -> Optional[int]:
        return self.metadata_cache_timeout.get("table_cache_timeout")

    @property
    def default_schemas(self) -> List[str]:
        return self.get_extra().get("default_schemas", [])

    @property
    def connect_args(self) -> Dict[str, Any]:
        return self.get_extra().get("engine_params", {}).get("connect_args", {})

    @property
    def engine_information(self) -> Dict[str, Any]:
        try:
            engine_information = self.db_engine_spec.get_public_information()
        except Exception:  # pylint: disable=broad-except
            engine_information = {}
        return engine_information

    @classmethod
    def get_password_masked_url_from_uri(  # pylint: disable=invalid-name
        cls, uri: str
    ) -> URL:
        sqlalchemy_url = make_url_safe(uri)
        return cls.get_password_masked_url(sqlalchemy_url)

    @classmethod
    def get_password_masked_url(cls, masked_url: URL) -> URL:
        url_copy = deepcopy(masked_url)
        if url_copy.password is not None:
            url_copy = url_copy.set(password=PASSWORD_MASK)
        return url_copy

    def set_sqlalchemy_uri(self, uri: str) -> None:
        conn = make_url_safe(uri.strip())
        if conn.password != PASSWORD_MASK and not custom_password_store:
            # do not over-write the password with the password mask
            self.password = conn.password
        conn = conn.set(password=PASSWORD_MASK if conn.password else None)
        self.sqlalchemy_uri = str(conn)  # hides the password

    def get_effective_user(self, object_url: URL) -> Optional[str]:
        """
        Get the effective user, especially during impersonation.

        :param object_url: SQL Alchemy URL object
        :return: The effective username
        """

        return (  # pylint: disable=used-before-assignment
            username
            if (username := get_username())
            else object_url.username
            if self.impersonate_user
            else None
        )

    @contextmanager
    def get_sqla_engine_with_context(
        self,
        schema: Optional[str] = None,
        nullpool: bool = True,
        source: Optional[utils.QuerySource] = None,
    ) -> Engine:
        yield self._get_sqla_engine(schema=schema, nullpool=nullpool, source=source)

    def _get_sqla_engine(
        self,
        schema: Optional[str] = None,
        nullpool: bool = True,
        source: Optional[utils.QuerySource] = None,
    ) -> Engine:
        extra = self.get_extra()
        sqlalchemy_url = make_url_safe(self.sqlalchemy_uri_decrypted)
        sqlalchemy_url = self.db_engine_spec.adjust_database_uri(sqlalchemy_url, schema)
        effective_username = self.get_effective_user(sqlalchemy_url)
        # If using MySQL or Presto for example, will set url.username
        # If using Hive, will not do anything yet since that relies on a
        # configuration parameter instead.
        sqlalchemy_url = self.db_engine_spec.get_url_for_impersonation(
            sqlalchemy_url, self.impersonate_user, effective_username
        )

        masked_url = self.get_password_masked_url(sqlalchemy_url)
        logger.debug("Database._get_sqla_engine(). Masked URL: %s", str(masked_url))

        params = extra.get("engine_params", {})
        if nullpool:
            params["poolclass"] = NullPool

        connect_args = params.get("connect_args", {})
        if self.impersonate_user:
            self.db_engine_spec.update_impersonation_config(
                connect_args, str(sqlalchemy_url), effective_username
            )

        if connect_args:
            params["connect_args"] = connect_args

        self.update_params_from_encrypted_extra(params)

        if DB_CONNECTION_MUTATOR:
            if not source and request and request.referrer:
                if "/superset/dashboard/" in request.referrer:
                    source = utils.QuerySource.DASHBOARD
                elif "/explore/" in request.referrer:
                    source = utils.QuerySource.CHART
                elif "/superset/sqllab" in request.referrer:
                    source = utils.QuerySource.SQL_LAB

            sqlalchemy_url, params = DB_CONNECTION_MUTATOR(
                sqlalchemy_url, params, effective_username, security_manager, source
            )

        try:
            return create_engine(sqlalchemy_url, **params)
        except Exception as ex:
            raise self.db_engine_spec.get_dbapi_mapped_exception(ex)

    @property
    def quote_identifier(self) -> Callable[[str], str]:
        """Add quotes to potential identifiter expressions if needed"""
        return self.get_dialect().identifier_preparer.quote

    def get_reserved_words(self) -> Set[str]:
        return self.get_dialect().preparer.reserved_words

    def get_df(  # pylint: disable=too-many-locals
        self,
        sql: str,
        schema: Optional[str] = None,
        mutator: Optional[Callable[[pd.DataFrame], None]] = None,
    ) -> pd.DataFrame:
        sqls = self.db_engine_spec.parse_sql(sql)
        engine = self._get_sqla_engine(schema)

        def needs_conversion(df_series: pd.Series) -> bool:
            return (
                not df_series.empty
                and isinstance(df_series, pd.Series)
                and isinstance(df_series[0], (list, dict))
            )

        def _log_query(sql: str) -> None:
            if log_query:
                log_query(
                    engine.url,
                    sql,
                    schema,
                    get_username(),
                    __name__,
                    security_manager,
                )

        with closing(engine.raw_connection()) as conn:
            cursor = conn.cursor()
            for sql_ in sqls[:-1]:
                _log_query(sql_)
                self.db_engine_spec.execute(cursor, sql_)
                cursor.fetchall()

            _log_query(sqls[-1])
            self.db_engine_spec.execute(cursor, sqls[-1])

            data = self.db_engine_spec.fetch_data(cursor)
            result_set = SupersetResultSet(
                data, cursor.description, self.db_engine_spec
            )
            df = result_set.to_pandas_df()
            if mutator:
                df = mutator(df)

            for col, coltype in df.dtypes.to_dict().items():
                if coltype == numpy.object_ and needs_conversion(df[col]):
                    df[col] = df[col].apply(utils.json_dumps_w_dates)

            return df

    def compile_sqla_query(self, qry: Select, schema: Optional[str] = None) -> str:
        engine = self._get_sqla_engine(schema=schema)

        sql = str(qry.compile(engine, compile_kwargs={"literal_binds": True}))

        # pylint: disable=protected-access
        if engine.dialect.identifier_preparer._double_percents:  # noqa
            sql = sql.replace("%%", "%")

        return sql

    def select_star(  # pylint: disable=too-many-arguments
        self,
        table_name: str,
        schema: Optional[str] = None,
        limit: int = 100,
        show_cols: bool = False,
        indent: bool = True,
        latest_partition: bool = False,
        cols: Optional[List[Dict[str, Any]]] = None,
    ) -> str:
        """Generates a ``select *`` statement in the proper dialect"""
        eng = self._get_sqla_engine(schema=schema, source=utils.QuerySource.SQL_LAB)
        return self.db_engine_spec.select_star(
            self,
            table_name,
            schema=schema,
            engine=eng,
            limit=limit,
            show_cols=show_cols,
            indent=indent,
            latest_partition=latest_partition,
            cols=cols,
        )

    def apply_limit_to_sql(
        self, sql: str, limit: int = 1000, force: bool = False
    ) -> str:
        if self.db_engine_spec.allow_limit_clause:
            return self.db_engine_spec.apply_limit_to_sql(sql, limit, self, force=force)
        return self.db_engine_spec.apply_top_to_sql(sql, limit)

    def safe_sqlalchemy_uri(self) -> str:
        return self.sqlalchemy_uri

    @property
    def inspector(self) -> Inspector:
        engine = self._get_sqla_engine()
        return sqla.inspect(engine)

    @cache_util.memoized_func(
        key="db:{self.id}:schema:{schema}:table_list",
        cache=cache_manager.cache,
    )
    def get_all_table_names_in_schema(  # pylint: disable=unused-argument
        self,
        schema: str,
        cache: bool = False,
        cache_timeout: Optional[int] = None,
        force: bool = False,
    ) -> Set[Tuple[str, str]]:
        """Parameters need to be passed as keyword arguments.

        For unused parameters, they are referenced in
        cache_util.memoized_func decorator.

        :param schema: schema name
        :param cache: whether cache is enabled for the function
        :param cache_timeout: timeout in seconds for the cache
        :param force: whether to force refresh the cache
        :return: The table/schema pairs
        """
        try:
            return {
                (table, schema)
                for table in self.db_engine_spec.get_table_names(
                    database=self,
                    inspector=self.inspector,
                    schema=schema,
                )
            }
        except Exception as ex:
            raise self.db_engine_spec.get_dbapi_mapped_exception(ex)

    @cache_util.memoized_func(
        key="db:{self.id}:schema:{schema}:view_list",
        cache=cache_manager.cache,
    )
    def get_all_view_names_in_schema(  # pylint: disable=unused-argument
        self,
        schema: str,
        cache: bool = False,
        cache_timeout: Optional[int] = None,
        force: bool = False,
    ) -> Set[Tuple[str, str]]:
        """Parameters need to be passed as keyword arguments.

        For unused parameters, they are referenced in
        cache_util.memoized_func decorator.

        :param schema: schema name
        :param cache: whether cache is enabled for the function
        :param cache_timeout: timeout in seconds for the cache
        :param force: whether to force refresh the cache
        :return: set of views
        """
        try:
            return {
                (view, schema)
                for view in self.db_engine_spec.get_view_names(
                    database=self,
                    inspector=self.inspector,
                    schema=schema,
                )
            }
        except Exception as ex:
            raise self.db_engine_spec.get_dbapi_mapped_exception(ex)

    @cache_util.memoized_func(
        key="db:{self.id}:schema_list",
        cache=cache_manager.cache,
    )
    def get_all_schema_names(  # pylint: disable=unused-argument
        self,
        cache: bool = False,
        cache_timeout: Optional[int] = None,
        force: bool = False,
    ) -> List[str]:
        """Parameters need to be passed as keyword arguments.

        For unused parameters, they are referenced in
        cache_util.memoized_func decorator.

        :param cache: whether cache is enabled for the function
        :param cache_timeout: timeout in seconds for the cache
        :param force: whether to force refresh the cache
        :return: schema list
        """
        try:
            return self.db_engine_spec.get_schema_names(self.inspector)
        except Exception as ex:
            raise self.db_engine_spec.get_dbapi_mapped_exception(ex) from ex

    @property
    def db_engine_spec(self) -> Type[db_engine_specs.BaseEngineSpec]:
        url = make_url_safe(self.sqlalchemy_uri_decrypted)
        return self.get_db_engine_spec(url)

    @classmethod
    @memoized
    def get_db_engine_spec(cls, url: URL) -> Type[db_engine_specs.BaseEngineSpec]:
        backend = url.get_backend_name()
        try:
            driver = url.get_driver_name()
        except NoSuchModuleError:
            # can't load the driver, fallback for backwards compatibility
            driver = None

        return db_engine_specs.get_engine_spec(backend, driver)

    def grains(self) -> Tuple[TimeGrain, ...]:
        """Defines time granularity database-specific expressions.

        The idea here is to make it easy for users to change the time grain
        from a datetime (maybe the source grain is arbitrary timestamps, daily
        or 5 minutes increments) to another, "truncated" datetime. Since
        each database has slightly different but similar datetime functions,
        this allows a mapping between database engines and actual functions.
        """
        return self.db_engine_spec.get_time_grains()

    def get_extra(self) -> Dict[str, Any]:
        return self.db_engine_spec.get_extra_params(self)

    def get_encrypted_extra(self) -> Dict[str, Any]:
        encrypted_extra = {}
        if self.encrypted_extra:
            try:
                encrypted_extra = json.loads(self.encrypted_extra)
            except json.JSONDecodeError as ex:
                logger.error(ex, exc_info=True)
                raise ex
        return encrypted_extra

    # pylint: disable=invalid-name
    def update_params_from_encrypted_extra(self, params: Dict[str, Any]) -> None:
        self.db_engine_spec.update_params_from_encrypted_extra(self, params)

    def get_table(self, table_name: str, schema: Optional[str] = None) -> Table:
        extra = self.get_extra()
        meta = MetaData(**extra.get("metadata_params", {}))
        return Table(
            table_name,
            meta,
            schema=schema or None,
            autoload=True,
            autoload_with=self._get_sqla_engine(),
        )

    def get_table_comment(
        self, table_name: str, schema: Optional[str] = None
    ) -> Optional[str]:
        return self.db_engine_spec.get_table_comment(self.inspector, table_name, schema)

    def get_columns(
        self, table_name: str, schema: Optional[str] = None
    ) -> List[Dict[str, Any]]:
        return self.db_engine_spec.get_columns(self.inspector, table_name, schema)

    def get_metrics(
        self,
        table_name: str,
        schema: Optional[str] = None,
    ) -> List[MetricType]:
        return self.db_engine_spec.get_metrics(self, self.inspector, table_name, schema)

    def get_indexes(
        self, table_name: str, schema: Optional[str] = None
    ) -> List[Dict[str, Any]]:
        indexes = self.inspector.get_indexes(table_name, schema)
        return self.db_engine_spec.normalize_indexes(indexes)

    def get_pk_constraint(
        self, table_name: str, schema: Optional[str] = None
    ) -> Dict[str, Any]:
        pk_constraint = self.inspector.get_pk_constraint(table_name, schema) or {}

        def _convert(value: Any) -> Any:
            try:
                return utils.base_json_conv(value)
            except TypeError:
                return None

        return {key: _convert(value) for key, value in pk_constraint.items()}

    def get_foreign_keys(
        self, table_name: str, schema: Optional[str] = None
    ) -> List[Dict[str, Any]]:
        return self.inspector.get_foreign_keys(table_name, schema)

    def get_schema_access_for_file_upload(  # pylint: disable=invalid-name
        self,
    ) -> List[str]:
        allowed_databases = self.get_extra().get("schemas_allowed_for_file_upload", [])

        if isinstance(allowed_databases, str):
            allowed_databases = literal_eval(allowed_databases)

        if hasattr(g, "user"):
            extra_allowed_databases = config["ALLOWED_USER_CSV_SCHEMA_FUNC"](
                self, g.user
            )
            allowed_databases += extra_allowed_databases
        return sorted(set(allowed_databases))

    @property
    def sqlalchemy_uri_decrypted(self) -> str:
        try:
            conn = make_url_safe(self.sqlalchemy_uri)
        except (ArgumentError, ValueError):
            # if the URI is invalid, ignore and return a placeholder url
            # (so users see 500 less often)
            return "dialect://invalid_uri"
        if custom_password_store:
            conn = conn.set(password=custom_password_store(conn))
        else:
            conn = conn.set(password=self.password)
        return str(conn)

    @property
    def sql_url(self) -> str:
        return f"/superset/sql/{self.id}/"

    @hybrid_property
    def perm(self) -> str:
        return f"[{self.database_name}].(id:{self.id})"

    @perm.expression  # type: ignore
    def perm(cls) -> str:  # pylint: disable=no-self-argument
        return (
            "[" + cls.database_name + "].(id:" + expression.cast(cls.id, String) + ")"
        )

    def get_perm(self) -> str:
        return self.perm  # type: ignore

    def has_table(self, table: Table) -> bool:
        engine = self._get_sqla_engine()
        return engine.has_table(table.table_name, table.schema or None)

    def has_table_by_name(self, table_name: str, schema: Optional[str] = None) -> bool:
        engine = self._get_sqla_engine()
        return engine.has_table(table_name, schema)

    @classmethod
    def _has_view(
        cls,
        conn: Connection,
        dialect: Dialect,
        view_name: str,
        schema: Optional[str] = None,
    ) -> bool:
        view_names: List[str] = []
        try:
            view_names = dialect.get_view_names(connection=conn, schema=schema)
        except Exception:  # pylint: disable=broad-except
            logger.warning("Has view failed", exc_info=True)
        return view_name in view_names

    def has_view(self, view_name: str, schema: Optional[str] = None) -> bool:
        engine = self._get_sqla_engine()
        return engine.run_callable(self._has_view, engine.dialect, view_name, schema)

    def has_view_by_name(self, view_name: str, schema: Optional[str] = None) -> bool:
        return self.has_view(view_name=view_name, schema=schema)

    @memoized
    def get_dialect(self) -> Dialect:
        sqla_url = make_url_safe(self.sqlalchemy_uri_decrypted)
        return sqla_url.get_dialect()()


sqla.event.listen(Database, "after_insert", security_manager.database_after_insert)
sqla.event.listen(Database, "after_update", security_manager.database_after_update)
sqla.event.listen(Database, "after_delete", security_manager.database_after_delete)


class Log(Model):  # pylint: disable=too-few-public-methods

    """ORM object used to log Superset actions to the database"""

    __tablename__ = "logs"

    id = Column(Integer, primary_key=True)
    action = Column(String(512))
    user_id = Column(Integer, ForeignKey("ab_user.id"))
    dashboard_id = Column(Integer)
    slice_id = Column(Integer)
    json = Column(Text)
    user = relationship(
        security_manager.user_model, backref="logs", foreign_keys=[user_id]
    )
    dttm = Column(DateTime, default=datetime.utcnow)
    duration_ms = Column(Integer)
    referrer = Column(String(1024))


class FavStarClassName(str, enum.Enum):
    CHART = "slice"
    DASHBOARD = "Dashboard"


class FavStar(Model):  # pylint: disable=too-few-public-methods
    __tablename__ = "favstar"

    id = Column(Integer, primary_key=True)
    user_id = Column(Integer, ForeignKey("ab_user.id"))
    class_name = Column(String(50))
    obj_id = Column(Integer)
    dttm = Column(DateTime, default=datetime.utcnow)