| # 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=unused-argument |
| import dataclasses |
| import hashlib |
| import json |
| import logging |
| import re |
| from contextlib import closing |
| from datetime import datetime |
| from typing import ( |
| Any, |
| Callable, |
| Dict, |
| List, |
| Match, |
| NamedTuple, |
| Optional, |
| Pattern, |
| Tuple, |
| Type, |
| TYPE_CHECKING, |
| Union, |
| ) |
| |
| import pandas as pd |
| import sqlparse |
| from flask import g |
| from flask_babel import lazy_gettext as _ |
| from sqlalchemy import column, DateTime, select |
| from sqlalchemy.engine.base import Engine |
| from sqlalchemy.engine.interfaces import Compiled, Dialect |
| from sqlalchemy.engine.reflection import Inspector |
| from sqlalchemy.engine.url import URL |
| from sqlalchemy.ext.compiler import compiles |
| from sqlalchemy.orm import Session |
| from sqlalchemy.sql import quoted_name, text |
| from sqlalchemy.sql.expression import ColumnClause, ColumnElement, Select, TextAsFrom |
| from sqlalchemy.types import TypeEngine |
| |
| from superset import app, security_manager, sql_parse |
| from superset.errors import ErrorLevel, SupersetError, SupersetErrorType |
| from superset.models.sql_lab import Query |
| from superset.sql_parse import ParsedQuery, Table |
| from superset.utils import core as utils |
| |
| if TYPE_CHECKING: |
| # prevent circular imports |
| from superset.connectors.sqla.models import TableColumn |
| from superset.models.core import Database |
| |
| logger = logging.getLogger() |
| |
| |
| class TimeGrain(NamedTuple): # pylint: disable=too-few-public-methods |
| name: str # TODO: redundant field, remove |
| label: str |
| function: str |
| duration: Optional[str] |
| |
| |
| QueryStatus = utils.QueryStatus |
| config = app.config |
| |
| builtin_time_grains: Dict[Optional[str], str] = { |
| None: "Time Column", |
| "PT1S": "second", |
| "PT1M": "minute", |
| "PT5M": "5 minute", |
| "PT10M": "10 minute", |
| "PT15M": "15 minute", |
| "PT0.5H": "half hour", |
| "PT1H": "hour", |
| "P1D": "day", |
| "P1W": "week", |
| "P1M": "month", |
| "P0.25Y": "quarter", |
| "P1Y": "year", |
| "1969-12-28T00:00:00Z/P1W": "week_start_sunday", |
| "1969-12-29T00:00:00Z/P1W": "week_start_monday", |
| "P1W/1970-01-03T00:00:00Z": "week_ending_saturday", |
| "P1W/1970-01-04T00:00:00Z": "week_ending_sunday", |
| } |
| |
| |
| class TimestampExpression( |
| ColumnClause |
| ): # pylint: disable=abstract-method,too-many-ancestors,too-few-public-methods |
| def __init__(self, expr: str, col: ColumnClause, **kwargs: Any) -> None: |
| """Sqlalchemy class that can be can be used to render native column elements |
| respeting engine-specific quoting rules as part of a string-based expression. |
| |
| :param expr: Sql expression with '{col}' denoting the locations where the col |
| object will be rendered. |
| :param col: the target column |
| """ |
| super().__init__(expr, **kwargs) |
| self.col = col |
| |
| @property |
| def _constructor(self) -> ColumnClause: |
| # Needed to ensure that the column label is rendered correctly when |
| # proxied to the outer query. |
| # See https://github.com/sqlalchemy/sqlalchemy/issues/4730 |
| return ColumnClause |
| |
| |
| @compiles(TimestampExpression) |
| def compile_timegrain_expression( |
| element: TimestampExpression, compiler: Compiled, **kwargs: Any |
| ) -> str: |
| return element.name.replace("{col}", compiler.process(element.col, **kwargs)) |
| |
| |
| class LimitMethod: # pylint: disable=too-few-public-methods |
| """Enum the ways that limits can be applied""" |
| |
| FETCH_MANY = "fetch_many" |
| WRAP_SQL = "wrap_sql" |
| FORCE_LIMIT = "force_limit" |
| |
| |
| class BaseEngineSpec: # pylint: disable=too-many-public-methods |
| """Abstract class for database engine specific configurations""" |
| |
| engine = "base" # str as defined in sqlalchemy.engine.engine |
| engine_aliases: Optional[Tuple[str]] = None |
| engine_name: Optional[ |
| str |
| ] = None # used for user messages, overridden in child classes |
| _date_trunc_functions: Dict[str, str] = {} |
| _time_grain_expressions: Dict[Optional[str], str] = {} |
| column_type_mappings: Tuple[ |
| Tuple[Pattern[str], Union[TypeEngine, Callable[[Match[str]], TypeEngine]]], ..., |
| ] = () |
| time_groupby_inline = False |
| limit_method = LimitMethod.FORCE_LIMIT |
| time_secondary_columns = False |
| allows_joins = True |
| allows_subqueries = True |
| allows_column_aliases = True |
| allows_sql_comments = True |
| force_column_alias_quotes = False |
| arraysize = 0 |
| max_column_name_length = 0 |
| try_remove_schema_from_table_name = True # pylint: disable=invalid-name |
| run_multiple_statements_as_one = False |
| |
| # default matching patterns to convert database specific column types to |
| # more generic types |
| db_column_types: Dict[utils.GenericDataType, Tuple[Pattern[str], ...]] = { |
| utils.GenericDataType.NUMERIC: ( |
| re.compile(r"BIT", re.IGNORECASE), |
| re.compile( |
| r".*(DOUBLE|FLOAT|INT|NUMBER|REAL|NUMERIC|DECIMAL|MONEY).*", |
| re.IGNORECASE, |
| ), |
| re.compile(r".*LONG$", re.IGNORECASE), |
| ), |
| utils.GenericDataType.STRING: ( |
| re.compile(r".*(CHAR|STRING|TEXT).*", re.IGNORECASE), |
| ), |
| utils.GenericDataType.TEMPORAL: ( |
| re.compile(r".*(DATE|TIME).*", re.IGNORECASE), |
| ), |
| } |
| |
| @classmethod |
| def get_dbapi_exception_mapping(cls) -> Dict[Type[Exception], Type[Exception]]: |
| """ |
| Each engine can implement and converge its own specific exceptions into |
| Superset DBAPI exceptions |
| |
| Note: On python 3.9 this method can be changed to a classmethod property |
| without the need of implementing a metaclass type |
| |
| :return: A map of driver specific exception to superset custom exceptions |
| """ |
| return {} |
| |
| @classmethod |
| def get_dbapi_mapped_exception(cls, exception: Exception) -> Exception: |
| """ |
| Get a superset custom DBAPI exception from the driver specific exception. |
| |
| Override if the engine needs to perform extra changes to the exception, for |
| example change the exception message or implement custom more complex logic |
| |
| :param exception: The driver specific exception |
| :return: Superset custom DBAPI exception |
| """ |
| new_exception = cls.get_dbapi_exception_mapping().get(type(exception)) |
| if not new_exception: |
| return exception |
| return new_exception(str(exception)) |
| |
| @classmethod |
| def is_db_column_type_match( |
| cls, db_column_type: Optional[str], target_column_type: utils.GenericDataType |
| ) -> bool: |
| """ |
| Check if a column type satisfies a pattern in a collection of regexes found in |
| `db_column_types`. For example, if `db_column_type == "NVARCHAR"`, |
| it would be a match for "STRING" due to being a match for the regex ".*CHAR.*". |
| |
| :param db_column_type: Column type to evaluate |
| :param target_column_type: The target type to evaluate for |
| :return: `True` if a `db_column_type` matches any pattern corresponding to |
| `target_column_type` |
| """ |
| if not db_column_type: |
| return False |
| patterns = cls.db_column_types[target_column_type] |
| return any(pattern.match(db_column_type) for pattern in patterns) |
| |
| @classmethod |
| def get_allow_cost_estimate(cls, extra: Dict[str, Any]) -> bool: |
| return False |
| |
| @classmethod |
| def get_engine( |
| cls, |
| database: "Database", |
| schema: Optional[str] = None, |
| source: Optional[str] = None, |
| ) -> Engine: |
| user_name = utils.get_username() |
| return database.get_sqla_engine( |
| schema=schema, nullpool=True, user_name=user_name, source=source |
| ) |
| |
| @classmethod |
| def get_timestamp_expr( |
| cls, |
| col: ColumnClause, |
| pdf: Optional[str], |
| time_grain: Optional[str], |
| type_: Optional[str] = None, |
| ) -> TimestampExpression: |
| """ |
| Construct a TimestampExpression to be used in a SQLAlchemy query. |
| |
| :param col: Target column for the TimestampExpression |
| :param pdf: date format (seconds or milliseconds) |
| :param time_grain: time grain, e.g. P1Y for 1 year |
| :param type_: the source column type |
| :return: TimestampExpression object |
| """ |
| if time_grain: |
| time_expr = cls.get_time_grain_expressions().get(time_grain) |
| if not time_expr: |
| raise NotImplementedError( |
| f"No grain spec for {time_grain} for database {cls.engine}" |
| ) |
| if type_ and "{func}" in time_expr: |
| date_trunc_function = cls._date_trunc_functions.get(type_) |
| if date_trunc_function: |
| time_expr = time_expr.replace("{func}", date_trunc_function) |
| if type_ and "{type}" in time_expr: |
| date_trunc_function = cls._date_trunc_functions.get(type_) |
| if date_trunc_function: |
| time_expr = time_expr.replace("{type}", type_) |
| else: |
| time_expr = "{col}" |
| |
| # if epoch, translate to DATE using db specific conf |
| if pdf == "epoch_s": |
| time_expr = time_expr.replace("{col}", cls.epoch_to_dttm()) |
| elif pdf == "epoch_ms": |
| time_expr = time_expr.replace("{col}", cls.epoch_ms_to_dttm()) |
| |
| return TimestampExpression(time_expr, col, type_=DateTime) |
| |
| @classmethod |
| def get_time_grains(cls) -> Tuple[TimeGrain, ...]: |
| """ |
| Generate a tuple of supported time grains. |
| |
| :return: All time grains supported by the engine |
| """ |
| |
| ret_list = [] |
| time_grains = builtin_time_grains.copy() |
| time_grains.update(config["TIME_GRAIN_ADDONS"]) |
| for duration, func in cls.get_time_grain_expressions().items(): |
| if duration in time_grains: |
| name = time_grains[duration] |
| ret_list.append(TimeGrain(name, _(name), func, duration)) |
| return tuple(ret_list) |
| |
| @classmethod |
| def get_time_grain_expressions(cls) -> Dict[Optional[str], str]: |
| """ |
| Return a dict of all supported time grains including any potential added grains |
| but excluding any potentially disabled grains in the config file. |
| |
| :return: All time grain expressions supported by the engine |
| """ |
| # TODO: use @memoize decorator or similar to avoid recomputation on every call |
| time_grain_expressions = cls._time_grain_expressions.copy() |
| grain_addon_expressions = config["TIME_GRAIN_ADDON_EXPRESSIONS"] |
| time_grain_expressions.update(grain_addon_expressions.get(cls.engine, {})) |
| denylist: List[str] = config["TIME_GRAIN_DENYLIST"] |
| for key in denylist: |
| time_grain_expressions.pop(key) |
| return time_grain_expressions |
| |
| @classmethod |
| def make_select_compatible( |
| cls, groupby_exprs: Dict[str, ColumnElement], select_exprs: List[ColumnElement] |
| ) -> List[ColumnElement]: |
| """ |
| Some databases will just return the group-by field into the select, but don't |
| allow the group-by field to be put into the select list. |
| |
| :param groupby_exprs: mapping between column name and column object |
| :param select_exprs: all columns in the select clause |
| :return: columns to be included in the final select clause |
| """ |
| return select_exprs |
| |
| @classmethod |
| def fetch_data( |
| cls, cursor: Any, limit: Optional[int] = None |
| ) -> List[Tuple[Any, ...]]: |
| """ |
| |
| :param cursor: Cursor instance |
| :param limit: Maximum number of rows to be returned by the cursor |
| :return: Result of query |
| """ |
| if cls.arraysize: |
| cursor.arraysize = cls.arraysize |
| try: |
| if cls.limit_method == LimitMethod.FETCH_MANY and limit: |
| return cursor.fetchmany(limit) |
| return cursor.fetchall() |
| except Exception as ex: |
| raise cls.get_dbapi_mapped_exception(ex) |
| |
| @classmethod |
| def expand_data( |
| cls, columns: List[Dict[Any, Any]], data: List[Dict[Any, Any]] |
| ) -> Tuple[List[Dict[Any, Any]], List[Dict[Any, Any]], List[Dict[Any, Any]]]: |
| """ |
| Some engines support expanding nested fields. See implementation in Presto |
| spec for details. |
| |
| :param columns: columns selected in the query |
| :param data: original data set |
| :return: list of all columns(selected columns and their nested fields), |
| expanded data set, listed of nested fields |
| """ |
| return columns, data, [] |
| |
| @classmethod |
| def alter_new_orm_column(cls, orm_col: "TableColumn") -> None: |
| """Allow altering default column attributes when first detected/added |
| |
| For instance special column like `__time` for Druid can be |
| set to is_dttm=True. Note that this only gets called when new |
| columns are detected/created""" |
| # TODO: Fix circular import caused by importing TableColumn |
| |
| @classmethod |
| def epoch_to_dttm(cls) -> str: |
| """ |
| SQL expression that converts epoch (seconds) to datetime that can be used in a |
| query. The reference column should be denoted as `{col}` in the return |
| expression, e.g. "FROM_UNIXTIME({col})" |
| |
| :return: SQL Expression |
| """ |
| raise NotImplementedError() |
| |
| @classmethod |
| def epoch_ms_to_dttm(cls) -> str: |
| """ |
| SQL expression that converts epoch (milliseconds) to datetime that can be used |
| in a query. |
| |
| :return: SQL Expression |
| """ |
| return cls.epoch_to_dttm().replace("{col}", "({col}/1000)") |
| |
| @classmethod |
| def get_datatype(cls, type_code: Any) -> Optional[str]: |
| """ |
| Change column type code from cursor description to string representation. |
| |
| :param type_code: Type code from cursor description |
| :return: String representation of type code |
| """ |
| if isinstance(type_code, str) and type_code != "": |
| return type_code.upper() |
| return None |
| |
| @classmethod |
| def normalize_indexes(cls, indexes: List[Dict[str, Any]]) -> List[Dict[str, Any]]: |
| """ |
| Normalizes indexes for more consistency across db engines |
| |
| noop by default |
| |
| :param indexes: Raw indexes as returned by SQLAlchemy |
| :return: cleaner, more aligned index definition |
| """ |
| return indexes |
| |
| @classmethod |
| def extra_table_metadata( |
| cls, database: "Database", table_name: str, schema_name: str |
| ) -> Dict[str, Any]: |
| """ |
| Returns engine-specific table metadata |
| |
| :param database: Database instance |
| :param table_name: Table name |
| :param schema_name: Schema name |
| :return: Engine-specific table metadata |
| """ |
| # TODO: Fix circular import caused by importing Database |
| return {} |
| |
| @classmethod |
| def apply_limit_to_sql(cls, sql: str, limit: int, database: "Database") -> str: |
| """ |
| Alters the SQL statement to apply a LIMIT clause |
| |
| :param sql: SQL query |
| :param limit: Maximum number of rows to be returned by the query |
| :param database: Database instance |
| :return: SQL query with limit clause |
| """ |
| # TODO: Fix circular import caused by importing Database |
| if cls.limit_method == LimitMethod.WRAP_SQL: |
| sql = sql.strip("\t\n ;") |
| qry = ( |
| select("*") |
| .select_from(TextAsFrom(text(sql), ["*"]).alias("inner_qry")) |
| .limit(limit) |
| ) |
| return database.compile_sqla_query(qry) |
| |
| if LimitMethod.FORCE_LIMIT: |
| parsed_query = sql_parse.ParsedQuery(sql) |
| sql = parsed_query.set_or_update_query_limit(limit) |
| |
| return sql |
| |
| @classmethod |
| def get_limit_from_sql(cls, sql: str) -> Optional[int]: |
| """ |
| Extract limit from SQL query |
| |
| :param sql: SQL query |
| :return: Value of limit clause in query |
| """ |
| parsed_query = sql_parse.ParsedQuery(sql) |
| return parsed_query.limit |
| |
| @classmethod |
| def set_or_update_query_limit(cls, sql: str, limit: int) -> str: |
| """ |
| Create a query based on original query but with new limit clause |
| |
| :param sql: SQL query |
| :param limit: New limit to insert/replace into query |
| :return: Query with new limit |
| """ |
| parsed_query = sql_parse.ParsedQuery(sql) |
| return parsed_query.set_or_update_query_limit(limit) |
| |
| @staticmethod |
| def csv_to_df(**kwargs: Any) -> pd.DataFrame: |
| """Read csv into Pandas DataFrame |
| :param kwargs: params to be passed to DataFrame.read_csv |
| :return: Pandas DataFrame containing data from csv |
| """ |
| kwargs["encoding"] = "utf-8" |
| kwargs["iterator"] = True |
| chunks = pd.read_csv(**kwargs) |
| df = pd.concat(chunk for chunk in chunks) |
| return df |
| |
| @classmethod |
| def df_to_sql(cls, df: pd.DataFrame, **kwargs: Any) -> None: |
| """Upload data from a Pandas DataFrame to a database. For |
| regular engines this calls the DataFrame.to_sql() method. Can be |
| overridden for engines that don't work well with to_sql(), e.g. |
| BigQuery. |
| :param df: Dataframe with data to be uploaded |
| :param kwargs: kwargs to be passed to to_sql() method |
| """ |
| df.to_sql(**kwargs) |
| |
| @classmethod |
| def create_table_from_csv( # pylint: disable=too-many-arguments |
| cls, |
| filename: str, |
| table: Table, |
| database: "Database", |
| csv_to_df_kwargs: Dict[str, Any], |
| df_to_sql_kwargs: Dict[str, Any], |
| ) -> None: |
| """ |
| Create table from contents of a csv. Note: this method does not create |
| metadata for the table. |
| """ |
| df = cls.csv_to_df(filepath_or_buffer=filename, **csv_to_df_kwargs) |
| engine = cls.get_engine(database) |
| if table.schema: |
| # only add schema when it is preset and non empty |
| df_to_sql_kwargs["schema"] = table.schema |
| if engine.dialect.supports_multivalues_insert: |
| df_to_sql_kwargs["method"] = "multi" |
| cls.df_to_sql(df=df, con=engine, **df_to_sql_kwargs) |
| |
| @classmethod |
| def convert_dttm(cls, target_type: str, dttm: datetime) -> Optional[str]: |
| """ |
| Convert Python datetime object to a SQL expression |
| |
| :param target_type: The target type of expression |
| :param dttm: The datetime object |
| :return: The SQL expression |
| """ |
| return None |
| |
| @classmethod |
| def create_table_from_excel( # pylint: disable=too-many-arguments |
| cls, |
| filename: str, |
| table: Table, |
| database: "Database", |
| excel_to_df_kwargs: Dict[str, Any], |
| df_to_sql_kwargs: Dict[str, Any], |
| ) -> None: |
| """ |
| Create table from contents of a excel. Note: this method does not create |
| metadata for the table. |
| """ |
| df = pd.read_excel(io=filename, **excel_to_df_kwargs) |
| engine = cls.get_engine(database) |
| if table.schema: |
| # only add schema when it is preset and non empty |
| df_to_sql_kwargs["schema"] = table.schema |
| if engine.dialect.supports_multivalues_insert: |
| df_to_sql_kwargs["method"] = "multi" |
| cls.df_to_sql(df=df, con=engine, **df_to_sql_kwargs) |
| |
| @classmethod |
| def get_all_datasource_names( |
| cls, database: "Database", datasource_type: str |
| ) -> List[utils.DatasourceName]: |
| """Returns a list of all tables or views in database. |
| |
| :param database: Database instance |
| :param datasource_type: Datasource_type can be 'table' or 'view' |
| :return: List of all datasources in database or schema |
| """ |
| # TODO: Fix circular import caused by importing Database |
| schemas = database.get_all_schema_names( |
| cache=database.schema_cache_enabled, |
| cache_timeout=database.schema_cache_timeout, |
| force=True, |
| ) |
| all_datasources: List[utils.DatasourceName] = [] |
| for schema in schemas: |
| if datasource_type == "table": |
| all_datasources += database.get_all_table_names_in_schema( |
| schema=schema, |
| force=True, |
| cache=database.table_cache_enabled, |
| cache_timeout=database.table_cache_timeout, |
| ) |
| elif datasource_type == "view": |
| all_datasources += database.get_all_view_names_in_schema( |
| schema=schema, |
| force=True, |
| cache=database.table_cache_enabled, |
| cache_timeout=database.table_cache_timeout, |
| ) |
| else: |
| raise Exception(f"Unsupported datasource_type: {datasource_type}") |
| return all_datasources |
| |
| @classmethod |
| def handle_cursor(cls, cursor: Any, query: Query, session: Session) -> None: |
| """Handle a live cursor between the execute and fetchall calls |
| |
| The flow works without this method doing anything, but it allows |
| for handling the cursor and updating progress information in the |
| query object""" |
| # TODO: Fix circular import error caused by importing sql_lab.Query |
| |
| @classmethod |
| def extract_error_message(cls, ex: Exception) -> str: |
| return f"{cls.engine} error: {cls._extract_error_message(ex)}" |
| |
| @classmethod |
| def _extract_error_message(cls, ex: Exception) -> str: |
| """Extract error message for queries""" |
| return utils.error_msg_from_exception(ex) |
| |
| @classmethod |
| def extract_errors(cls, ex: Exception) -> List[Dict[str, Any]]: |
| return [ |
| dataclasses.asdict( |
| SupersetError( |
| error_type=SupersetErrorType.GENERIC_DB_ENGINE_ERROR, |
| message=cls._extract_error_message(ex), |
| level=ErrorLevel.ERROR, |
| extra={"engine_name": cls.engine_name}, |
| ) |
| ) |
| ] |
| |
| @classmethod |
| def adjust_database_uri(cls, uri: URL, selected_schema: Optional[str]) -> None: |
| """ |
| Mutate the database component of the SQLAlchemy URI. |
| |
| The URI here represents the URI as entered when saving the database, |
| ``selected_schema`` is the schema currently active presumably in |
| the SQL Lab dropdown. Based on that, for some database engine, |
| we can return a new altered URI that connects straight to the |
| active schema, meaning the users won't have to prefix the object |
| names by the schema name. |
| |
| Some databases engines have 2 level of namespacing: database and |
| schema (postgres, oracle, mssql, ...) |
| For those it's probably better to not alter the database |
| component of the URI with the schema name, it won't work. |
| |
| Some database drivers like presto accept '{catalog}/{schema}' in |
| the database component of the URL, that can be handled here. |
| """ |
| |
| @classmethod |
| def patch(cls) -> None: |
| """ |
| TODO: Improve docstring and refactor implementation in Hive |
| """ |
| |
| @classmethod |
| def get_schema_names(cls, inspector: Inspector) -> List[str]: |
| """ |
| Get all schemas from database |
| |
| :param inspector: SqlAlchemy inspector |
| :return: All schemas in the database |
| """ |
| return sorted(inspector.get_schema_names()) |
| |
| @classmethod |
| def get_table_names( |
| cls, database: "Database", inspector: Inspector, schema: Optional[str] |
| ) -> List[str]: |
| """ |
| Get all tables from schema |
| |
| :param inspector: SqlAlchemy inspector |
| :param schema: Schema to inspect. If omitted, uses default schema for database |
| :return: All tables in schema |
| """ |
| tables = inspector.get_table_names(schema) |
| if schema and cls.try_remove_schema_from_table_name: |
| tables = [re.sub(f"^{schema}\\.", "", table) for table in tables] |
| return sorted(tables) |
| |
| @classmethod |
| def get_view_names( |
| cls, database: "Database", inspector: Inspector, schema: Optional[str] |
| ) -> List[str]: |
| """ |
| Get all views from schema |
| |
| :param inspector: SqlAlchemy inspector |
| :param schema: Schema name. If omitted, uses default schema for database |
| :return: All views in schema |
| """ |
| views = inspector.get_view_names(schema) |
| if schema and cls.try_remove_schema_from_table_name: |
| views = [re.sub(f"^{schema}\\.", "", view) for view in views] |
| return sorted(views) |
| |
| @classmethod |
| def get_table_comment( |
| cls, inspector: Inspector, table_name: str, schema: Optional[str] |
| ) -> Optional[str]: |
| """ |
| Get comment of table from a given schema and table |
| |
| :param inspector: SqlAlchemy Inspector instance |
| :param table_name: Table name |
| :param schema: Schema name. If omitted, uses default schema for database |
| :return: comment of table |
| """ |
| comment = None |
| try: |
| comment = inspector.get_table_comment(table_name, schema) |
| comment = comment.get("text") if isinstance(comment, dict) else None |
| except NotImplementedError: |
| # It's expected that some dialects don't implement the comment method |
| pass |
| except Exception as ex: # pylint: disable=broad-except |
| logger.error("Unexpected error while fetching table comment") |
| logger.exception(ex) |
| return comment |
| |
| @classmethod |
| def get_columns( |
| cls, inspector: Inspector, table_name: str, schema: Optional[str] |
| ) -> List[Dict[str, Any]]: |
| """ |
| Get all columns from a given schema and table |
| |
| :param inspector: SqlAlchemy Inspector instance |
| :param table_name: Table name |
| :param schema: Schema name. If omitted, uses default schema for database |
| :return: All columns in table |
| """ |
| return inspector.get_columns(table_name, schema) |
| |
| @classmethod |
| def where_latest_partition( # pylint: disable=too-many-arguments |
| cls, |
| table_name: str, |
| schema: Optional[str], |
| database: "Database", |
| query: Select, |
| columns: Optional[List[Dict[str, str]]] = None, |
| ) -> Optional[Select]: |
| """ |
| Add a where clause to a query to reference only the most recent partition |
| |
| :param table_name: Table name |
| :param schema: Schema name |
| :param database: Database instance |
| :param query: SqlAlchemy query |
| :param columns: List of TableColumns |
| :return: SqlAlchemy query with additional where clause referencing latest |
| partition |
| """ |
| # TODO: Fix circular import caused by importing Database, TableColumn |
| return None |
| |
| @classmethod |
| def _get_fields(cls, cols: List[Dict[str, Any]]) -> List[Any]: |
| return [column(c["name"]) for c in cols] |
| |
| @classmethod |
| def select_star( # pylint: disable=too-many-arguments,too-many-locals |
| cls, |
| database: "Database", |
| table_name: str, |
| engine: Engine, |
| schema: Optional[str] = None, |
| limit: int = 100, |
| show_cols: bool = False, |
| indent: bool = True, |
| latest_partition: bool = True, |
| cols: Optional[List[Dict[str, Any]]] = None, |
| ) -> str: |
| """ |
| Generate a "SELECT * from [schema.]table_name" query with appropriate limit. |
| |
| WARNING: expects only unquoted table and schema names. |
| |
| :param database: Database instance |
| :param table_name: Table name, unquoted |
| :param engine: SqlALchemy Engine instance |
| :param schema: Schema, unquoted |
| :param limit: limit to impose on query |
| :param show_cols: Show columns in query; otherwise use "*" |
| :param indent: Add indentation to query |
| :param latest_partition: Only query latest partition |
| :param cols: Columns to include in query |
| :return: SQL query |
| """ |
| fields: Union[str, List[Any]] = "*" |
| cols = cols or [] |
| if (show_cols or latest_partition) and not cols: |
| cols = database.get_columns(table_name, schema) |
| |
| if show_cols: |
| fields = cls._get_fields(cols) |
| quote = engine.dialect.identifier_preparer.quote |
| if schema: |
| full_table_name = quote(schema) + "." + quote(table_name) |
| else: |
| full_table_name = quote(table_name) |
| |
| qry = select(fields).select_from(text(full_table_name)) |
| |
| if limit: |
| qry = qry.limit(limit) |
| if latest_partition: |
| partition_query = cls.where_latest_partition( |
| table_name, schema, database, qry, columns=cols |
| ) |
| if partition_query is not None: |
| qry = partition_query |
| sql = database.compile_sqla_query(qry) |
| if indent: |
| sql = sqlparse.format(sql, reindent=True) |
| return sql |
| |
| @classmethod |
| def estimate_statement_cost(cls, statement: str, cursor: Any,) -> Dict[str, Any]: |
| """ |
| Generate a SQL query that estimates the cost of a given statement. |
| |
| :param statement: A single SQL statement |
| :param cursor: Cursor instance |
| :return: Dictionary with different costs |
| """ |
| raise Exception("Database does not support cost estimation") |
| |
| @classmethod |
| def query_cost_formatter( |
| cls, raw_cost: List[Dict[str, Any]] |
| ) -> List[Dict[str, str]]: |
| """ |
| Format cost estimate. |
| |
| :param raw_cost: Raw estimate from `estimate_query_cost` |
| :return: Human readable cost estimate |
| """ |
| raise Exception("Database does not support cost estimation") |
| |
| @classmethod |
| def process_statement( |
| cls, statement: str, database: "Database", user_name: str |
| ) -> str: |
| """ |
| Process a SQL statement by stripping and mutating it. |
| |
| :param statement: A single SQL statement |
| :param database: Database instance |
| :param username: Effective username |
| :return: Dictionary with different costs |
| """ |
| parsed_query = ParsedQuery(statement) |
| sql = parsed_query.stripped() |
| sql_query_mutator = config["SQL_QUERY_MUTATOR"] |
| if sql_query_mutator: |
| sql = sql_query_mutator(sql, user_name, security_manager, database) |
| |
| return sql |
| |
| @classmethod |
| def estimate_query_cost( |
| cls, database: "Database", schema: str, sql: str, source: Optional[str] = None |
| ) -> List[Dict[str, Any]]: |
| """ |
| Estimate the cost of a multiple statement SQL query. |
| |
| :param database: Database instance |
| :param schema: Database schema |
| :param sql: SQL query with possibly multiple statements |
| :param source: Source of the query (eg, "sql_lab") |
| """ |
| extra = database.get_extra() or {} |
| if not cls.get_allow_cost_estimate(extra): |
| raise Exception("Database does not support cost estimation") |
| |
| user_name = g.user.username if g.user else None |
| parsed_query = sql_parse.ParsedQuery(sql) |
| statements = parsed_query.get_statements() |
| |
| engine = cls.get_engine(database, schema=schema, source=source) |
| costs = [] |
| with closing(engine.raw_connection()) as conn: |
| cursor = conn.cursor() |
| for statement in statements: |
| processed_statement = cls.process_statement( |
| statement, database, user_name |
| ) |
| costs.append(cls.estimate_statement_cost(processed_statement, cursor)) |
| return costs |
| |
| @classmethod |
| def modify_url_for_impersonation( |
| cls, url: URL, impersonate_user: bool, username: Optional[str] |
| ) -> None: |
| """ |
| Modify the SQL Alchemy URL object with the user to impersonate if applicable. |
| :param url: SQLAlchemy URL object |
| :param impersonate_user: Flag indicating if impersonation is enabled |
| :param username: Effective username |
| """ |
| if impersonate_user and username is not None: |
| url.username = username |
| |
| @classmethod |
| def update_impersonation_config( |
| cls, connect_args: Dict[str, Any], uri: str, username: Optional[str], |
| ) -> None: |
| """ |
| Update a configuration dictionary |
| that can set the correct properties for impersonating users |
| |
| :param connect_args: config to be updated |
| :param uri: URI |
| :param impersonate_user: Flag indicating if impersonation is enabled |
| :param username: Effective username |
| :return: None |
| """ |
| |
| @classmethod |
| def execute(cls, cursor: Any, query: str, **kwargs: Any) -> None: |
| """ |
| Execute a SQL query |
| |
| :param cursor: Cursor instance |
| :param query: Query to execute |
| :param kwargs: kwargs to be passed to cursor.execute() |
| :return: |
| """ |
| if not cls.allows_sql_comments: |
| query = sql_parse.strip_comments_from_sql(query) |
| |
| if cls.arraysize: |
| cursor.arraysize = cls.arraysize |
| try: |
| cursor.execute(query) |
| except Exception as ex: |
| raise cls.get_dbapi_mapped_exception(ex) |
| |
| @classmethod |
| def make_label_compatible(cls, label: str) -> Union[str, quoted_name]: |
| """ |
| Conditionally mutate and/or quote a sqlalchemy expression label. If |
| force_column_alias_quotes is set to True, return the label as a |
| sqlalchemy.sql.elements.quoted_name object to ensure that the select query |
| and query results have same case. Otherwise return the mutated label as a |
| regular string. If maxmimum supported column name length is exceeded, |
| generate a truncated label by calling truncate_label(). |
| |
| :param label: expected expression label/alias |
| :return: conditionally mutated label supported by the db engine |
| """ |
| label_mutated = cls._mutate_label(label) |
| if ( |
| cls.max_column_name_length |
| and len(label_mutated) > cls.max_column_name_length |
| ): |
| label_mutated = cls._truncate_label(label) |
| if cls.force_column_alias_quotes: |
| label_mutated = quoted_name(label_mutated, True) |
| return label_mutated |
| |
| @classmethod |
| def get_sqla_column_type(cls, type_: Optional[str]) -> Optional[TypeEngine]: |
| """ |
| Return a sqlalchemy native column type that corresponds to the column type |
| defined in the data source (return None to use default type inferred by |
| SQLAlchemy). Override `column_type_mappings` for specific needs |
| (see MSSQL for example of NCHAR/NVARCHAR handling). |
| |
| :param type_: Column type returned by inspector |
| :return: SqlAlchemy column type |
| """ |
| if not type_: |
| return None |
| for regex, sqla_type in cls.column_type_mappings: |
| match = regex.match(type_) |
| if match: |
| if callable(sqla_type): |
| return sqla_type(match) |
| return sqla_type |
| return None |
| |
| @staticmethod |
| def _mutate_label(label: str) -> str: |
| """ |
| Most engines support mixed case aliases that can include numbers |
| and special characters, like commas, parentheses etc. For engines that |
| have restrictions on what types of aliases are supported, this method |
| can be overridden to ensure that labels conform to the engine's |
| limitations. Mutated labels should be deterministic (input label A always |
| yields output label X) and unique (input labels A and B don't yield the same |
| output label X). |
| |
| :param label: Preferred expression label |
| :return: Conditionally mutated label |
| """ |
| return label |
| |
| @classmethod |
| def _truncate_label(cls, label: str) -> str: |
| """ |
| In the case that a label exceeds the max length supported by the engine, |
| this method is used to construct a deterministic and unique label based on |
| the original label. By default this returns an md5 hash of the original label, |
| conditionally truncated if the length of the hash exceeds the max column length |
| of the engine. |
| |
| :param label: Expected expression label |
| :return: Truncated label |
| """ |
| label = hashlib.md5(label.encode("utf-8")).hexdigest() |
| # truncate hash if it exceeds max length |
| if cls.max_column_name_length and len(label) > cls.max_column_name_length: |
| label = label[: cls.max_column_name_length] |
| return label |
| |
| @classmethod |
| def column_datatype_to_string( |
| cls, sqla_column_type: TypeEngine, dialect: Dialect |
| ) -> str: |
| """ |
| Convert sqlalchemy column type to string representation. |
| By default removes collation and character encoding info to avoid unnecessarily |
| long datatypes. |
| |
| :param sqla_column_type: SqlAlchemy column type |
| :param dialect: Sqlalchemy dialect |
| :return: Compiled column type |
| """ |
| sqla_column_type = sqla_column_type.copy() |
| if hasattr(sqla_column_type, "collation"): |
| sqla_column_type.collation = None |
| if hasattr(sqla_column_type, "charset"): |
| sqla_column_type.charset = None |
| return sqla_column_type.compile(dialect=dialect).upper() |
| |
| @classmethod |
| def get_function_names(cls, database: "Database") -> List[str]: |
| """ |
| Get a list of function names that are able to be called on the database. |
| Used for SQL Lab autocomplete. |
| |
| :param database: The database to get functions for |
| :return: A list of function names useable in the database |
| """ |
| return [] |
| |
| @staticmethod |
| def pyodbc_rows_to_tuples(data: List[Any]) -> List[Tuple[Any, ...]]: |
| """ |
| Convert pyodbc.Row objects from `fetch_data` to tuples. |
| |
| :param data: List of tuples or pyodbc.Row objects |
| :return: List of tuples |
| """ |
| if data and type(data[0]).__name__ == "Row": |
| data = [tuple(row) for row in data] |
| return data |
| |
| @staticmethod |
| def mutate_db_for_connection_test(database: "Database") -> None: |
| """ |
| Some databases require passing additional parameters for validating database |
| connections. This method makes it possible to mutate the database instance prior |
| to testing if a connection is ok. |
| |
| :param database: instance to be mutated |
| """ |
| return None |
| |
| @staticmethod |
| def get_extra_params(database: "Database") -> Dict[str, Any]: |
| """ |
| Some databases require adding elements to connection parameters, |
| like passing certificates to `extra`. This can be done here. |
| |
| :param database: database instance from which to extract extras |
| :raises CertificateException: If certificate is not valid/unparseable |
| """ |
| extra: Dict[str, Any] = {} |
| if database.extra: |
| try: |
| extra = json.loads(database.extra) |
| except json.JSONDecodeError as ex: |
| logger.error(ex) |
| raise ex |
| return extra |
| |
| @classmethod |
| def is_readonly_query(cls, parsed_query: ParsedQuery) -> bool: |
| """Pessimistic readonly, 100% sure statement won't mutate anything""" |
| return parsed_query.is_select() or parsed_query.is_explain() |
