# 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. import logging import re import textwrap import time from collections import defaultdict, deque from contextlib import closing from datetime import datetime from distutils.version import StrictVersion from typing import Any, cast, Dict, List, Optional, Tuple, TYPE_CHECKING from urllib import parse import pandas as pd import simplejson as json from sqlalchemy import Column, literal_column from sqlalchemy.engine.base import Engine from sqlalchemy.engine.reflection import Inspector from sqlalchemy.engine.result import RowProxy from sqlalchemy.engine.url import URL from sqlalchemy.orm import Session from sqlalchemy.sql.expression import ColumnClause, Select from superset import app, cache, is_feature_enabled, security_manager from superset.db_engine_specs.base import BaseEngineSpec from superset.exceptions import SupersetTemplateException from superset.models.sql_lab import Query from superset.models.sql_types.presto_sql_types import type_map as presto_type_map from superset.sql_parse import ParsedQuery from superset.utils import core as utils if TYPE_CHECKING: # prevent circular imports from superset.models.core import Database # pylint: disable=unused-import QueryStatus = utils.QueryStatus config = app.config logger = logging.getLogger(__name__) def get_children(column: Dict[str, str]) -> List[Dict[str, str]]: """ Get the children of a complex Presto type (row or array). For arrays, we return a single list with the base type: >>> get_children(dict(name="a", type="ARRAY(BIGINT)")) [{"name": "a", "type": "BIGINT"}] For rows, we return a list of the columns: >>> get_children(dict(name="a", type="ROW(BIGINT,FOO VARCHAR)")) [{'name': 'a._col0', 'type': 'BIGINT'}, {'name': 'a.foo', 'type': 'VARCHAR'}] :param column: dictionary representing a Presto column :return: list of dictionaries representing children columns """ pattern = re.compile(r"(?P\w+)\((?P.*)\)") match = pattern.match(column["type"]) if not match: raise Exception(f"Unable to parse column type {column['type']}") group = match.groupdict() type_ = group["type"].upper() children_type = group["children"] if type_ == "ARRAY": return [{"name": column["name"], "type": children_type}] elif type_ == "ROW": nameless_columns = 0 columns = [] for child in utils.split(children_type, ","): parts = list(utils.split(child.strip(), " ")) if len(parts) == 2: name, type_ = parts name = name.strip('"') else: name = f"_col{nameless_columns}" type_ = parts[0] nameless_columns += 1 columns.append({"name": f"{column['name']}.{name.lower()}", "type": type_}) return columns else: raise Exception(f"Unknown type {type_}!") class PrestoEngineSpec(BaseEngineSpec): engine = "presto" _time_grain_functions = { None: "{col}", "PT1S": "date_trunc('second', CAST({col} AS TIMESTAMP))", "PT1M": "date_trunc('minute', CAST({col} AS TIMESTAMP))", "PT1H": "date_trunc('hour', CAST({col} AS TIMESTAMP))", "P1D": "date_trunc('day', CAST({col} AS TIMESTAMP))", "P1W": "date_trunc('week', CAST({col} AS TIMESTAMP))", "P1M": "date_trunc('month', CAST({col} AS TIMESTAMP))", "P0.25Y": "date_trunc('quarter', CAST({col} AS TIMESTAMP))", "P1Y": "date_trunc('year', CAST({col} AS TIMESTAMP))", "P1W/1970-01-03T00:00:00Z": "date_add('day', 5, date_trunc('week', " "date_add('day', 1, CAST({col} AS TIMESTAMP))))", "1969-12-28T00:00:00Z/P1W": "date_add('day', -1, date_trunc('week', " "date_add('day', 1, CAST({col} AS TIMESTAMP))))", } @classmethod def get_allow_cost_estimate(cls, version: Optional[str] = None) -> bool: return version is not None and StrictVersion(version) >= StrictVersion("0.319") @classmethod def get_table_names( cls, database: "Database", inspector: Inspector, schema: Optional[str] ) -> List[str]: tables = super().get_table_names(database, inspector, schema) if not is_feature_enabled("PRESTO_SPLIT_VIEWS_FROM_TABLES"): return tables views = set(cls.get_view_names(database, inspector, schema)) actual_tables = set(tables) - views return list(actual_tables) @classmethod def get_view_names( cls, database: "Database", inspector: Inspector, schema: Optional[str] ) -> List[str]: """Returns an empty list get_table_names() function returns all table names and view names, and get_view_names() is not implemented in sqlalchemy_presto.py https://github.com/dropbox/PyHive/blob/e25fc8440a0686bbb7a5db5de7cb1a77bdb4167a/pyhive/sqlalchemy_presto.py """ if not is_feature_enabled("PRESTO_SPLIT_VIEWS_FROM_TABLES"): return [] if schema: sql = ( "SELECT table_name FROM information_schema.views " "WHERE table_schema=%(schema)s" ) params = {"schema": schema} else: sql = "SELECT table_name FROM information_schema.views" params = {} engine = cls.get_engine(database, schema=schema) with closing(engine.raw_connection()) as conn: with closing(conn.cursor()) as cursor: cursor.execute(sql, params) results = cursor.fetchall() return [row[0] for row in results] @classmethod def _create_column_info(cls, name: str, data_type: str) -> dict: """ Create column info object :param name: column name :param data_type: column data type :return: column info object """ return {"name": name, "type": f"{data_type}"} @classmethod def _get_full_name(cls, names: List[Tuple[str, str]]) -> str: """ Get the full column name :param names: list of all individual column names :return: full column name """ return ".".join(column[0] for column in names if column[0]) @classmethod def _has_nested_data_types(cls, component_type: str) -> bool: """ Check if string contains a data type. We determine if there is a data type by whitespace or multiple data types by commas :param component_type: data type :return: boolean """ comma_regex = r",(?=(?:[^\"]*\"[^\"]*\")*[^\"]*$)" white_space_regex = r"\s(?=(?:[^\"]*\"[^\"]*\")*[^\"]*$)" return ( re.search(comma_regex, component_type) is not None or re.search(white_space_regex, component_type) is not None ) @classmethod def _split_data_type(cls, data_type: str, delimiter: str) -> List[str]: """ Split data type based on given delimiter. Do not split the string if the delimiter is enclosed in quotes :param data_type: data type :param delimiter: string separator (i.e. open parenthesis, closed parenthesis, comma, whitespace) :return: list of strings after breaking it by the delimiter """ return re.split( r"{}(?=(?:[^\"]*\"[^\"]*\")*[^\"]*$)".format(delimiter), data_type ) @classmethod def _parse_structural_column( # pylint: disable=too-many-locals,too-many-branches cls, parent_column_name: str, parent_data_type: str, result: List[dict] ) -> None: """ Parse a row or array column :param result: list tracking the results """ formatted_parent_column_name = parent_column_name # Quote the column name if there is a space if " " in parent_column_name: formatted_parent_column_name = f'"{parent_column_name}"' full_data_type = f"{formatted_parent_column_name} {parent_data_type}" original_result_len = len(result) # split on open parenthesis ( to get the structural # data type and its component types data_types = cls._split_data_type(full_data_type, r"\(") stack: List[Tuple[str, str]] = [] for data_type in data_types: # split on closed parenthesis ) to track which component # types belong to what structural data type inner_types = cls._split_data_type(data_type, r"\)") for inner_type in inner_types: # We have finished parsing multiple structural data types if not inner_type and stack: stack.pop() elif cls._has_nested_data_types(inner_type): # split on comma , to get individual data types single_fields = cls._split_data_type(inner_type, ",") for single_field in single_fields: single_field = single_field.strip() # If component type starts with a comma, the first single field # will be an empty string. Disregard this empty string. if not single_field: continue # split on whitespace to get field name and data type field_info = cls._split_data_type(single_field, r"\s") # check if there is a structural data type within # overall structural data type if field_info[1] == "array" or field_info[1] == "row": stack.append((field_info[0], field_info[1])) full_parent_path = cls._get_full_name(stack) result.append( cls._create_column_info( full_parent_path, presto_type_map[field_info[1]]() ) ) else: # otherwise this field is a basic data type full_parent_path = cls._get_full_name(stack) column_name = "{}.{}".format( full_parent_path, field_info[0] ) result.append( cls._create_column_info( column_name, presto_type_map[field_info[1]]() ) ) # If the component type ends with a structural data type, do not pop # the stack. We have run across a structural data type within the # overall structural data type. Otherwise, we have completely parsed # through the entire structural data type and can move on. if not (inner_type.endswith("array") or inner_type.endswith("row")): stack.pop() # We have an array of row objects (i.e. array(row(...))) elif inner_type == "array" or inner_type == "row": # Push a dummy object to represent the structural data type stack.append(("", inner_type)) # We have an array of a basic data types(i.e. array(varchar)). elif stack: # Because it is an array of a basic data type. We have finished # parsing the structural data type and can move on. stack.pop() # Unquote the column name if necessary if formatted_parent_column_name != parent_column_name: for index in range(original_result_len, len(result)): result[index]["name"] = result[index]["name"].replace( formatted_parent_column_name, parent_column_name ) @classmethod def _show_columns( cls, inspector: Inspector, table_name: str, schema: Optional[str] ) -> List[RowProxy]: """ Show presto column names :param inspector: object that performs database schema inspection :param table_name: table name :param schema: schema name :return: list of column objects """ quote = inspector.engine.dialect.identifier_preparer.quote_identifier full_table = quote(table_name) if schema: full_table = "{}.{}".format(quote(schema), full_table) columns = inspector.bind.execute("SHOW COLUMNS FROM {}".format(full_table)) return columns @classmethod def get_columns( cls, inspector: Inspector, table_name: str, schema: Optional[str] ) -> List[Dict[str, Any]]: """ Get columns from a Presto data source. This includes handling row and array data types :param inspector: object that performs database schema inspection :param table_name: table name :param schema: schema name :return: a list of results that contain column info (i.e. column name and data type) """ columns = cls._show_columns(inspector, table_name, schema) result: List[dict] = [] for column in columns: try: # parse column if it is a row or array if is_feature_enabled("PRESTO_EXPAND_DATA") and ( "array" in column.Type or "row" in column.Type ): structural_column_index = len(result) cls._parse_structural_column(column.Column, column.Type, result) result[structural_column_index]["nullable"] = getattr( column, "Null", True ) result[structural_column_index]["default"] = None continue else: # otherwise column is a basic data type column_type = presto_type_map[column.Type]() except KeyError: logger.info( "Did not recognize type {} of column {}".format( # pylint: disable=logging-format-interpolation column.Type, column.Column ) ) column_type = "OTHER" column_info = cls._create_column_info(column.Column, column_type) column_info["nullable"] = getattr(column, "Null", True) column_info["default"] = None result.append(column_info) return result @classmethod def _is_column_name_quoted(cls, column_name: str) -> bool: """ Check if column name is in quotes :param column_name: column name :return: boolean """ return column_name.startswith('"') and column_name.endswith('"') @classmethod def _get_fields(cls, cols: List[dict]) -> List[ColumnClause]: """ Format column clauses where names are in quotes and labels are specified :param cols: columns :return: column clauses """ column_clauses = [] # Column names are separated by periods. This regex will find periods in a # string if they are not enclosed in quotes because if a period is enclosed in # quotes, then that period is part of a column name. dot_pattern = r"""\. # split on period (?= # look ahead (?: # create non-capture group [^\"]*\"[^\"]*\" # two quotes )*[^\"]*$) # end regex""" dot_regex = re.compile(dot_pattern, re.VERBOSE) for col in cols: # get individual column names col_names = re.split(dot_regex, col["name"]) # quote each column name if it is not already quoted for index, col_name in enumerate(col_names): if not cls._is_column_name_quoted(col_name): col_names[index] = '"{}"'.format(col_name) quoted_col_name = ".".join( col_name if cls._is_column_name_quoted(col_name) else f'"{col_name}"' for col_name in col_names ) # create column clause in the format "name"."name" AS "name.name" column_clause = literal_column(quoted_col_name).label(col["name"]) column_clauses.append(column_clause) return column_clauses @classmethod def select_star( # pylint: disable=too-many-arguments cls, database: "Database", table_name: str, engine: Engine, schema: Optional[str] = None, limit: int = 100, show_cols: bool = False, indent: bool = True, latest_partition: bool = True, cols: Optional[List[Dict[str, Any]]] = None, ) -> str: """ Include selecting properties of row objects. We cannot easily break arrays into rows, so render the whole array in its own row and skip columns that correspond to an array's contents. """ cols = cols or [] presto_cols = cols if is_feature_enabled("PRESTO_EXPAND_DATA") and show_cols: dot_regex = r"\.(?=(?:[^\"]*\"[^\"]*\")*[^\"]*$)" presto_cols = [ col for col in presto_cols if not re.search(dot_regex, col["name"]) ] return super().select_star( database, table_name, engine, schema, limit, show_cols, indent, latest_partition, presto_cols, ) @classmethod def estimate_statement_cost( # pylint: disable=too-many-locals cls, statement: str, database: "Database", cursor: Any, user_name: str ) -> Dict[str, Any]: """ Run a SQL query that estimates the cost of a given statement. :param statement: A single SQL statement :param database: Database instance :param cursor: Cursor instance :param username: Effective username :return: JSON response from Presto """ 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) sql = f"EXPLAIN (TYPE IO, FORMAT JSON) {sql}" cursor.execute(sql) # the output from Presto is a single column and a single row containing # JSON: # # { # ... # "estimate" : { # "outputRowCount" : 8.73265878E8, # "outputSizeInBytes" : 3.41425774958E11, # "cpuCost" : 3.41425774958E11, # "maxMemory" : 0.0, # "networkCost" : 3.41425774958E11 # } # } result = json.loads(cursor.fetchone()[0]) return result @classmethod def query_cost_formatter( cls, raw_cost: List[Dict[str, Any]] ) -> List[Dict[str, str]]: """ Format cost estimate. :param raw_cost: JSON estimate from Presto :return: Human readable cost estimate """ def humanize(value: Any, suffix: str) -> str: try: value = int(value) except ValueError: return str(value) prefixes = ["K", "M", "G", "T", "P", "E", "Z", "Y"] prefix = "" to_next_prefix = 1000 while value > to_next_prefix and prefixes: prefix = prefixes.pop(0) value //= to_next_prefix return f"{value} {prefix}{suffix}" cost = [] columns = [ ("outputRowCount", "Output count", " rows"), ("outputSizeInBytes", "Output size", "B"), ("cpuCost", "CPU cost", ""), ("maxMemory", "Max memory", "B"), ("networkCost", "Network cost", ""), ] for row in raw_cost: estimate: Dict[str, float] = row.get("estimate", {}) statement_cost = {} for key, label, suffix in columns: if key in estimate: statement_cost[label] = humanize(estimate[key], suffix).strip() cost.append(statement_cost) return cost @classmethod def adjust_database_uri( cls, uri: URL, selected_schema: Optional[str] = None ) -> None: database = uri.database if selected_schema and database: selected_schema = parse.quote(selected_schema, safe="") if "/" in database: database = database.split("/")[0] + "/" + selected_schema else: database += "/" + selected_schema uri.database = database @classmethod def convert_dttm(cls, target_type: str, dttm: datetime) -> Optional[str]: tt = target_type.upper() if tt == "DATE": return f"""from_iso8601_date('{dttm.date().isoformat()}')""" if tt == "TIMESTAMP": return f"""from_iso8601_timestamp('{dttm.isoformat(timespec="microseconds")}')""" # pylint: disable=line-too-long return None @classmethod def epoch_to_dttm(cls) -> str: return "from_unixtime({col})" @classmethod def get_all_datasource_names( cls, database: "Database", datasource_type: str ) -> List[utils.DatasourceName]: datasource_df = database.get_df( "SELECT table_schema, table_name FROM INFORMATION_SCHEMA.{}S " "ORDER BY concat(table_schema, '.', table_name)".format( datasource_type.upper() ), None, ) datasource_names: List[utils.DatasourceName] = [] for _unused, row in datasource_df.iterrows(): datasource_names.append( utils.DatasourceName( schema=row["table_schema"], table=row["table_name"] ) ) return datasource_names @classmethod def expand_data( # pylint: disable=too-many-locals cls, columns: List[dict], data: List[dict] ) -> Tuple[List[dict], List[dict], List[dict]]: """ We do not immediately display rows and arrays clearly in the data grid. This method separates out nested fields and data values to help clearly display structural columns. Example: ColumnA is a row(nested_obj varchar) and ColumnB is an array(int) Original data set = [ {'ColumnA': ['a1'], 'ColumnB': [1, 2]}, {'ColumnA': ['a2'], 'ColumnB': [3, 4]}, ] Expanded data set = [ {'ColumnA': ['a1'], 'ColumnA.nested_obj': 'a1', 'ColumnB': 1}, {'ColumnA': '', 'ColumnA.nested_obj': '', 'ColumnB': 2}, {'ColumnA': ['a2'], 'ColumnA.nested_obj': 'a2', 'ColumnB': 3}, {'ColumnA': '', 'ColumnA.nested_obj': '', 'ColumnB': 4}, ] :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 """ if not is_feature_enabled("PRESTO_EXPAND_DATA"): return columns, data, [] # process each column, unnesting ARRAY types and # expanding ROW types into new columns to_process = deque((column, 0) for column in columns) all_columns: List[dict] = [] expanded_columns = [] current_array_level = None while to_process: column, level = to_process.popleft() if column["name"] not in [column["name"] for column in all_columns]: all_columns.append(column) # When unnesting arrays we need to keep track of how many extra rows # were added, for each original row. This is necessary when we expand # multiple arrays, so that the arrays after the first reuse the rows # added by the first. every time we change a level in the nested arrays # we reinitialize this. if level != current_array_level: unnested_rows: Dict[int, int] = defaultdict(int) current_array_level = level name = column["name"] if column["type"].startswith("ARRAY("): # keep processing array children; we append to the right so that # multiple nested arrays are processed breadth-first to_process.append((get_children(column)[0], level + 1)) # unnest array objects data into new rows i = 0 while i < len(data): row = data[i] values = row.get(name) if values: # how many extra rows we need to unnest the data? extra_rows = len(values) - 1 # how many rows were already added for this row? current_unnested_rows = unnested_rows[i] # add any necessary rows missing = extra_rows - current_unnested_rows for _ in range(missing): data.insert(i + current_unnested_rows + 1, {}) unnested_rows[i] += 1 # unnest array into rows for j, value in enumerate(values): data[i + j][name] = value # skip newly unnested rows i += unnested_rows[i] i += 1 if column["type"].startswith("ROW("): # expand columns; we append them to the left so they are added # immediately after the parent expanded = get_children(column) to_process.extendleft((column, level) for column in expanded) expanded_columns.extend(expanded) # expand row objects into new columns for row in data: for value, col in zip(row.get(name) or [], expanded): row[col["name"]] = value data = [ {k["name"]: row.get(k["name"], "") for k in all_columns} for row in data ] return all_columns, data, expanded_columns @classmethod def extra_table_metadata( cls, database: "Database", table_name: str, schema_name: str ) -> Dict[str, Any]: metadata = {} indexes = database.get_indexes(table_name, schema_name) if indexes: cols = indexes[0].get("column_names", []) full_table_name = table_name if schema_name and "." not in table_name: full_table_name = "{}.{}".format(schema_name, table_name) pql = cls._partition_query(full_table_name, database) col_names, latest_parts = cls.latest_partition( table_name, schema_name, database, show_first=True ) if not latest_parts: latest_parts = tuple([None] * len(col_names)) # type: ignore metadata["partitions"] = { "cols": cols, "latest": dict(zip(col_names, latest_parts)), # type: ignore "partitionQuery": pql, } # flake8 is not matching `Optional[str]` to `Any` for some reason... metadata["view"] = cast( Any, cls.get_create_view(database, schema_name, table_name) ) return metadata @classmethod def get_create_view( cls, database: "Database", schema: str, table: str ) -> Optional[str]: """ Return a CREATE VIEW statement, or `None` if not a view. :param database: Database instance :param schema: Schema name :param table: Table (view) name """ from pyhive.exc import DatabaseError engine = cls.get_engine(database, schema) with closing(engine.raw_connection()) as conn: with closing(conn.cursor()) as cursor: sql = f"SHOW CREATE VIEW {schema}.{table}" try: cls.execute(cursor, sql) polled = cursor.poll() while polled: time.sleep(0.2) polled = cursor.poll() except DatabaseError: # not a VIEW return None rows = cls.fetch_data(cursor, 1) return rows[0][0] @classmethod def handle_cursor(cls, cursor: Any, query: Query, session: Session) -> None: """Updates progress information""" query_id = query.id logger.info(f"Query {query_id}: Polling the cursor for progress") polled = cursor.poll() # poll returns dict -- JSON status information or ``None`` # if the query is done # https://github.com/dropbox/PyHive/blob/ # b34bdbf51378b3979eaf5eca9e956f06ddc36ca0/pyhive/presto.py#L178 while polled: # Update the object and wait for the kill signal. stats = polled.get("stats", {}) query = session.query(type(query)).filter_by(id=query_id).one() if query.status in [QueryStatus.STOPPED, QueryStatus.TIMED_OUT]: cursor.cancel() break if stats: state = stats.get("state") # if already finished, then stop polling if state == "FINISHED": break completed_splits = float(stats.get("completedSplits")) total_splits = float(stats.get("totalSplits")) if total_splits and completed_splits: progress = 100 * (completed_splits / total_splits) logger.info( "Query {} progress: {} / {} " # pylint: disable=logging-format-interpolation "splits".format(query_id, completed_splits, total_splits) ) if progress > query.progress: query.progress = progress session.commit() time.sleep(1) logger.info(f"Query {query_id}: Polling the cursor for progress") polled = cursor.poll() @classmethod def _extract_error_message(cls, e: Exception) -> Optional[str]: if ( hasattr(e, "orig") and type(e.orig).__name__ == "DatabaseError" # type: ignore and isinstance(e.orig[0], dict) # type: ignore ): error_dict = e.orig[0] # type: ignore return "{} at {}: {}".format( error_dict.get("errorName"), error_dict.get("errorLocation"), error_dict.get("message"), ) if type(e).__name__ == "DatabaseError" and hasattr(e, "args") and e.args: error_dict = e.args[0] return error_dict.get("message") return utils.error_msg_from_exception(e) @classmethod def _partition_query( # pylint: disable=too-many-arguments,too-many-locals cls, table_name: str, database: "Database", limit: int = 0, order_by: Optional[List[Tuple[str, bool]]] = None, filters: Optional[Dict[Any, Any]] = None, ) -> str: """Returns a partition query :param table_name: the name of the table to get partitions from :type table_name: str :param limit: the number of partitions to be returned :type limit: int :param order_by: a list of tuples of field name and a boolean that determines if that field should be sorted in descending order :type order_by: list of (str, bool) tuples :param filters: dict of field name and filter value combinations """ limit_clause = "LIMIT {}".format(limit) if limit else "" order_by_clause = "" if order_by: l = [] for field, desc in order_by: l.append(field + " DESC" if desc else "") order_by_clause = "ORDER BY " + ", ".join(l) where_clause = "" if filters: l = [] for field, value in filters.items(): l.append(f"{field} = '{value}'") where_clause = "WHERE " + " AND ".join(l) presto_version = database.get_extra().get("version") # Partition select syntax changed in v0.199, so check here. # Default to the new syntax if version is unset. partition_select_clause = ( f'SELECT * FROM "{table_name}$partitions"' if not presto_version or StrictVersion(presto_version) >= StrictVersion("0.199") else f"SHOW PARTITIONS FROM {table_name}" ) sql = textwrap.dedent( f"""\ {partition_select_clause} {where_clause} {order_by_clause} {limit_clause} """ ) return sql @classmethod def where_latest_partition( # pylint: disable=too-many-arguments cls, table_name: str, schema: Optional[str], database: "Database", query: Select, columns: Optional[List] = None, ) -> Optional[Select]: try: col_names, values = cls.latest_partition( table_name, schema, database, show_first=True ) except Exception: # pylint: disable=broad-except # table is not partitioned return None if values is None: return None column_names = {column.get("name") for column in columns or []} for col_name, value in zip(col_names, values): if col_name in column_names: query = query.where(Column(col_name) == value) return query @classmethod def _latest_partition_from_df( # pylint: disable=invalid-name cls, df: pd.DataFrame ) -> Optional[List[str]]: if not df.empty: return df.to_records(index=False)[0].item() return None @classmethod def latest_partition( cls, table_name: str, schema: Optional[str], database: "Database", show_first: bool = False, ) -> Tuple[List[str], Optional[List[str]]]: """Returns col name and the latest (max) partition value for a table :param table_name: the name of the table :param schema: schema / database / namespace :param database: database query will be run against :type database: models.Database :param show_first: displays the value for the first partitioning key if there are many partitioning keys :type show_first: bool >>> latest_partition('foo_table') (['ds'], ('2018-01-01',)) """ indexes = database.get_indexes(table_name, schema) if not indexes: raise SupersetTemplateException( f"Error getting partition for {schema}.{table_name}. " "Verify that this table has a partition." ) if len(indexes[0]["column_names"]) < 1: raise SupersetTemplateException( "The table should have one partitioned field" ) elif not show_first and len(indexes[0]["column_names"]) > 1: raise SupersetTemplateException( "The table should have a single partitioned field " "to use this function. You may want to use " "`presto.latest_sub_partition`" ) column_names = indexes[0]["column_names"] part_fields = [(column_name, True) for column_name in column_names] sql = cls._partition_query(table_name, database, 1, part_fields) df = database.get_df(sql, schema) return column_names, cls._latest_partition_from_df(df) @classmethod def latest_sub_partition( cls, table_name: str, schema: Optional[str], database: "Database", **kwargs: Any ) -> Any: """Returns the latest (max) partition value for a table A filtering criteria should be passed for all fields that are partitioned except for the field to be returned. For example, if a table is partitioned by (``ds``, ``event_type`` and ``event_category``) and you want the latest ``ds``, you'll want to provide a filter as keyword arguments for both ``event_type`` and ``event_category`` as in ``latest_sub_partition('my_table', event_category='page', event_type='click')`` :param table_name: the name of the table, can be just the table name or a fully qualified table name as ``schema_name.table_name`` :type table_name: str :param schema: schema / database / namespace :type schema: str :param database: database query will be run against :type database: models.Database :param kwargs: keyword arguments define the filtering criteria on the partition list. There can be many of these. :type kwargs: str >>> latest_sub_partition('sub_partition_table', event_type='click') '2018-01-01' """ indexes = database.get_indexes(table_name, schema) part_fields = indexes[0]["column_names"] for k in kwargs.keys(): # pylint: disable=consider-iterating-dictionary if k not in k in part_fields: msg = "Field [{k}] is not part of the portioning key" raise SupersetTemplateException(msg) if len(kwargs.keys()) != len(part_fields) - 1: msg = ( "A filter needs to be specified for {} out of the " "{} fields." ).format(len(part_fields) - 1, len(part_fields)) raise SupersetTemplateException(msg) for field in part_fields: if field not in kwargs.keys(): field_to_return = field sql = cls._partition_query( table_name, database, 1, [(field_to_return, True)], kwargs ) df = database.get_df(sql, schema) if df.empty: return "" return df.to_dict()[field_to_return][0] @classmethod @cache.memoize() 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 database.get_df("SHOW FUNCTIONS")["Function"].tolist()