superset/sql_parse.py
# 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=too-many-lines
from __future__ import annotations
import enum
import logging
import re
import urllib.parse
from collections.abc import Iterable, Iterator
from dataclasses import dataclass
from typing import Any, cast, Generic, TYPE_CHECKING, TypeVar
import sqlglot
import sqlparse
from flask_babel import gettext as __
from jinja2 import nodes
from sqlalchemy import and_
from sqlglot import exp, parse, parse_one
from sqlglot.dialects.dialect import Dialect, Dialects
from sqlglot.errors import ParseError, SqlglotError
from sqlglot.optimizer.scope import Scope, ScopeType, traverse_scope
from sqlparse import keywords
from sqlparse.lexer import Lexer
from sqlparse.sql import (
Identifier,
IdentifierList,
Parenthesis,
remove_quotes,
Token,
TokenList,
Where,
)
from sqlparse.tokens import (
Comment,
CTE,
DDL,
DML,
Keyword,
Name,
Punctuation,
String,
Whitespace,
Wildcard,
)
from sqlparse.utils import imt
from superset.errors import ErrorLevel, SupersetError, SupersetErrorType
from superset.exceptions import (
QueryClauseValidationException,
SupersetParseError,
SupersetSecurityException,
)
from superset.utils.backports import StrEnum
try:
from sqloxide import parse_sql as sqloxide_parse
except (ImportError, ModuleNotFoundError):
sqloxide_parse = None
if TYPE_CHECKING:
from superset.models.core import Database
RESULT_OPERATIONS = {"UNION", "INTERSECT", "EXCEPT", "SELECT"}
ON_KEYWORD = "ON"
PRECEDES_TABLE_NAME = {"FROM", "JOIN", "DESCRIBE", "WITH", "LEFT JOIN", "RIGHT JOIN"}
CTE_PREFIX = "CTE__"
logger = logging.getLogger(__name__)
# TODO: Workaround for https://github.com/andialbrecht/sqlparse/issues/652.
# configure the Lexer to extend sqlparse
# reference: https://sqlparse.readthedocs.io/en/stable/extending/
lex = Lexer.get_default_instance()
sqlparser_sql_regex = keywords.SQL_REGEX
sqlparser_sql_regex.insert(25, (r"'(''|\\\\|\\|[^'])*'", sqlparse.tokens.String.Single))
lex.set_SQL_REGEX(sqlparser_sql_regex)
# mapping between DB engine specs and sqlglot dialects
SQLGLOT_DIALECTS = {
"ascend": Dialects.HIVE,
"awsathena": Dialects.PRESTO,
"bigquery": Dialects.BIGQUERY,
"clickhouse": Dialects.CLICKHOUSE,
"clickhousedb": Dialects.CLICKHOUSE,
"cockroachdb": Dialects.POSTGRES,
# "crate": ???
# "databend": ???
"databricks": Dialects.DATABRICKS,
# "db2": ???
# "dremio": ???
"drill": Dialects.DRILL,
# "druid": ???
"duckdb": Dialects.DUCKDB,
# "dynamodb": ???
# "elasticsearch": ???
# "exa": ???
# "firebird": ???
# "firebolt": ???
"gsheets": Dialects.SQLITE,
"hana": Dialects.POSTGRES,
"hive": Dialects.HIVE,
# "ibmi": ???
# "impala": ???
# "kustokql": ???
# "kylin": ???
"mssql": Dialects.TSQL,
"mysql": Dialects.MYSQL,
"netezza": Dialects.POSTGRES,
# "ocient": ???
# "odelasticsearch": ???
"oracle": Dialects.ORACLE,
# "pinot": ???
"postgresql": Dialects.POSTGRES,
"presto": Dialects.PRESTO,
"pydoris": Dialects.DORIS,
"redshift": Dialects.REDSHIFT,
# "risingwave": ???
# "rockset": ???
"shillelagh": Dialects.SQLITE,
"snowflake": Dialects.SNOWFLAKE,
# "solr": ???
"spark": Dialects.SPARK,
"sqlite": Dialects.SQLITE,
"starrocks": Dialects.STARROCKS,
"superset": Dialects.SQLITE,
"teradatasql": Dialects.TERADATA,
"trino": Dialects.TRINO,
"vertica": Dialects.POSTGRES,
}
class CtasMethod(StrEnum):
TABLE = "TABLE"
VIEW = "VIEW"
def _extract_limit_from_query(statement: TokenList) -> int | None:
"""
Extract limit clause from SQL statement.
:param statement: SQL statement
:return: Limit extracted from query, None if no limit present in statement
"""
idx, _ = statement.token_next_by(m=(Keyword, "LIMIT"))
if idx is not None:
_, token = statement.token_next(idx=idx)
if token:
if isinstance(token, IdentifierList):
# In case of "LIMIT <offset>, <limit>", find comma and extract
# first succeeding non-whitespace token
idx, _ = token.token_next_by(m=(sqlparse.tokens.Punctuation, ","))
_, token = token.token_next(idx=idx)
if token and token.ttype == sqlparse.tokens.Literal.Number.Integer:
return int(token.value)
return None
def extract_top_from_query(statement: TokenList, top_keywords: set[str]) -> int | None:
"""
Extract top clause value from SQL statement.
:param statement: SQL statement
:param top_keywords: keywords that are considered as synonyms to TOP
:return: top value extracted from query, None if no top value present in statement
"""
str_statement = str(statement)
str_statement = str_statement.replace("\n", " ").replace("\r", "")
token = str_statement.rstrip().split(" ")
token = [part for part in token if part]
top = None
for i, part in enumerate(token):
if part.upper() in top_keywords and len(token) - 1 > i:
try:
top = int(token[i + 1])
except ValueError:
top = None
break
return top
def get_cte_remainder_query(sql: str) -> tuple[str | None, str]:
"""
parse the SQL and return the CTE and rest of the block to the caller
:param sql: SQL query
:return: CTE and remainder block to the caller
"""
cte: str | None = None
remainder = sql
stmt = sqlparse.parse(sql)[0]
# The first meaningful token for CTE will be with WITH
idx, token = stmt.token_next(-1, skip_ws=True, skip_cm=True)
if not (token and token.ttype == CTE):
return cte, remainder
idx, token = stmt.token_next(idx)
idx = stmt.token_index(token) + 1
# extract rest of the SQLs after CTE
remainder = "".join(str(token) for token in stmt.tokens[idx:]).strip()
cte = f"WITH {token.value}"
return cte, remainder
def strip_comments_from_sql(statement: str, engine: str | None = None) -> str:
"""
Strips comments from a SQL statement, does a simple test first
to avoid always instantiating the expensive ParsedQuery constructor
This is useful for engines that don't support comments
:param statement: A string with the SQL statement
:return: SQL statement without comments
"""
return (
ParsedQuery(statement, engine=engine).strip_comments()
if "--" in statement
else statement
)
@dataclass(eq=True, frozen=True)
class Table:
"""
A fully qualified SQL table conforming to [[catalog.]schema.]table.
"""
table: str
schema: str | None = None
catalog: str | None = None
def __str__(self) -> str:
"""
Return the fully qualified SQL table name.
"""
return ".".join(
urllib.parse.quote(part, safe="").replace(".", "%2E")
for part in [self.catalog, self.schema, self.table]
if part
)
def __eq__(self, __o: object) -> bool:
return str(self) == str(__o)
def extract_tables_from_statement(
statement: exp.Expression,
dialect: Dialects | None,
) -> set[Table]:
"""
Extract all table references in a single statement.
Please not that this is not trivial; consider the following queries:
DESCRIBE some_table;
SHOW PARTITIONS FROM some_table;
WITH masked_name AS (SELECT * FROM some_table) SELECT * FROM masked_name;
See the unit tests for other tricky cases.
"""
sources: Iterable[exp.Table]
if isinstance(statement, exp.Describe):
# A `DESCRIBE` query has no sources in sqlglot, so we need to explicitly
# query for all tables.
sources = statement.find_all(exp.Table)
elif isinstance(statement, exp.Command):
# Commands, like `SHOW COLUMNS FROM foo`, have to be converted into a
# `SELECT` statetement in order to extract tables.
literal = statement.find(exp.Literal)
if not literal:
return set()
try:
pseudo_query = parse_one(f"SELECT {literal.this}", dialect=dialect)
except ParseError:
return set()
sources = pseudo_query.find_all(exp.Table)
else:
sources = [
source
for scope in traverse_scope(statement)
for source in scope.sources.values()
if isinstance(source, exp.Table) and not is_cte(source, scope)
]
return {
Table(
source.name,
source.db if source.db != "" else None,
source.catalog if source.catalog != "" else None,
)
for source in sources
}
def is_cte(source: exp.Table, scope: Scope) -> bool:
"""
Is the source a CTE?
CTEs in the parent scope look like tables (and are represented by
exp.Table objects), but should not be considered as such;
otherwise a user with access to table `foo` could access any table
with a query like this:
WITH foo AS (SELECT * FROM target_table) SELECT * FROM foo
"""
parent_sources = scope.parent.sources if scope.parent else {}
ctes_in_scope = {
name
for name, parent_scope in parent_sources.items()
if isinstance(parent_scope, Scope) and parent_scope.scope_type == ScopeType.CTE
}
return source.name in ctes_in_scope
# To avoid unnecessary parsing/formatting of queries, the statement has the concept of
# an "internal representation", which is the AST of the SQL statement. For most of the
# engines supported by Superset this is `sqlglot.exp.Expression`, but there is a special
# case: KustoKQL uses a different syntax and there are no Python parsers for it, so we
# store the AST as a string (the original query), and manipulate it with regular
# expressions.
InternalRepresentation = TypeVar("InternalRepresentation")
# The base type. This helps type checking the `split_query` method correctly, since each
# derived class has a more specific return type (the class itself). This will no longer
# be needed once Python 3.11 is the lowest version supported. See PEP 673 for more
# information: https://peps.python.org/pep-0673/
TBaseSQLStatement = TypeVar("TBaseSQLStatement") # pylint: disable=invalid-name
class BaseSQLStatement(Generic[InternalRepresentation]):
"""
Base class for SQL statements.
The class can be instantiated with a string representation of the query or, for
efficiency reasons, with a pre-parsed AST. This is useful with `sqlglot.parse`,
which will split a query in multiple already parsed statements.
The `engine` parameters comes from the `engine` attribute in a Superset DB engine
spec.
"""
def __init__(
self,
statement: str | InternalRepresentation,
engine: str,
):
self._parsed: InternalRepresentation = (
self._parse_statement(statement, engine)
if isinstance(statement, str)
else statement
)
self.engine = engine
self.tables = self._extract_tables_from_statement(self._parsed, self.engine)
@classmethod
def split_query(
cls: type[TBaseSQLStatement],
query: str,
engine: str,
) -> list[TBaseSQLStatement]:
"""
Split a query into multiple instantiated statements.
This is a helper function to split a full SQL query into multiple
`BaseSQLStatement` instances. It's used by `SQLScript` when instantiating the
statements within a query.
"""
raise NotImplementedError()
@classmethod
def _parse_statement(
cls,
statement: str,
engine: str,
) -> InternalRepresentation:
"""
Parse a string containing a single SQL statement, and returns the parsed AST.
Derived classes should not assume that `statement` contains a single statement,
and MUST explicitly validate that. Since this validation is parser dependent the
responsibility is left to the children classes.
"""
raise NotImplementedError()
@classmethod
def _extract_tables_from_statement(
cls,
parsed: InternalRepresentation,
engine: str,
) -> set[Table]:
"""
Extract all table references in a given statement.
"""
raise NotImplementedError()
def format(self, comments: bool = True) -> str:
"""
Format the statement, optionally ommitting comments.
"""
raise NotImplementedError()
def get_settings(self) -> dict[str, str | bool]:
"""
Return any settings set by the statement.
For example, for this statement:
sql> SET foo = 'bar';
The method should return `{"foo": "'bar'"}`. Note the single quotes.
"""
raise NotImplementedError()
def __str__(self) -> str:
return self.format()
class SQLStatement(BaseSQLStatement[exp.Expression]):
"""
A SQL statement.
This class is used for all engines with dialects that can be parsed using sqlglot.
"""
def __init__(
self,
statement: str | exp.Expression,
engine: str,
):
self._dialect = SQLGLOT_DIALECTS.get(engine)
super().__init__(statement, engine)
@classmethod
def split_query(
cls,
query: str,
engine: str,
) -> list[SQLStatement]:
dialect = SQLGLOT_DIALECTS.get(engine)
try:
statements = sqlglot.parse(query, dialect=dialect)
except sqlglot.errors.ParseError as ex:
raise SupersetParseError("Unable to split query") from ex
return [cls(statement, engine) for statement in statements if statement]
@classmethod
def _parse_statement(
cls,
statement: str,
engine: str,
) -> exp.Expression:
"""
Parse a single SQL statement.
"""
dialect = SQLGLOT_DIALECTS.get(engine)
# We could parse with `sqlglot.parse_one` to get a single statement, but we need
# to verify that the string contains exactly one statement.
try:
statements = sqlglot.parse(statement, dialect=dialect)
except sqlglot.errors.ParseError as ex:
raise SupersetParseError("Unable to split query") from ex
statements = [statement for statement in statements if statement]
if len(statements) != 1:
raise SupersetParseError("SQLStatement should have exactly one statement")
return statements[0]
@classmethod
def _extract_tables_from_statement(
cls,
parsed: exp.Expression,
engine: str,
) -> set[Table]:
"""
Find all referenced tables.
"""
dialect = SQLGLOT_DIALECTS.get(engine)
return extract_tables_from_statement(parsed, dialect)
def format(self, comments: bool = True) -> str:
"""
Pretty-format the SQL statement.
"""
write = Dialect.get_or_raise(self._dialect)
return write.generate(self._parsed, copy=False, comments=comments, pretty=True)
def get_settings(self) -> dict[str, str | bool]:
"""
Return the settings for the SQL statement.
>>> statement = SQLStatement("SET foo = 'bar'")
>>> statement.get_settings()
{"foo": "'bar'"}
"""
return {
eq.this.sql(): eq.expression.sql()
for set_item in self._parsed.find_all(exp.SetItem)
for eq in set_item.find_all(exp.EQ)
}
class KQLSplitState(enum.Enum):
"""
State machine for splitting a KQL query.
The state machine keeps track of whether we're inside a string or not, so we
don't split the query in a semi-colon that's part of a string.
"""
OUTSIDE_STRING = enum.auto()
INSIDE_SINGLE_QUOTED_STRING = enum.auto()
INSIDE_DOUBLE_QUOTED_STRING = enum.auto()
INSIDE_MULTILINE_STRING = enum.auto()
def split_kql(kql: str) -> list[str]:
"""
Custom function for splitting KQL statements.
"""
statements = []
state = KQLSplitState.OUTSIDE_STRING
statement_start = 0
query = kql if kql.endswith(";") else kql + ";"
for i, character in enumerate(query):
if state == KQLSplitState.OUTSIDE_STRING:
if character == ";":
statements.append(query[statement_start:i])
statement_start = i + 1
elif character == "'":
state = KQLSplitState.INSIDE_SINGLE_QUOTED_STRING
elif character == '"':
state = KQLSplitState.INSIDE_DOUBLE_QUOTED_STRING
elif character == "`" and query[i - 2 : i] == "``":
state = KQLSplitState.INSIDE_MULTILINE_STRING
elif (
state == KQLSplitState.INSIDE_SINGLE_QUOTED_STRING
and character == "'"
and query[i - 1] != "\\"
):
state = KQLSplitState.OUTSIDE_STRING
elif (
state == KQLSplitState.INSIDE_DOUBLE_QUOTED_STRING
and character == '"'
and query[i - 1] != "\\"
):
state = KQLSplitState.OUTSIDE_STRING
elif (
state == KQLSplitState.INSIDE_MULTILINE_STRING
and character == "`"
and query[i - 2 : i] == "``"
):
state = KQLSplitState.OUTSIDE_STRING
return statements
class KustoKQLStatement(BaseSQLStatement[str]):
"""
Special class for Kusto KQL.
Kusto KQL is a SQL-like language, but it's not supported by sqlglot. Queries look
like this:
StormEvents
| summarize PropertyDamage = sum(DamageProperty) by State
| join kind=innerunique PopulationData on State
| project State, PropertyDamagePerCapita = PropertyDamage / Population
| sort by PropertyDamagePerCapita
See https://learn.microsoft.com/en-us/azure/data-explorer/kusto/query/ for more
details about it.
"""
@classmethod
def split_query(
cls,
query: str,
engine: str,
) -> list[KustoKQLStatement]:
"""
Split a query at semi-colons.
Since we don't have a parser, we use a simple state machine based function. See
https://learn.microsoft.com/en-us/azure/data-explorer/kusto/query/scalar-data-types/string
for more information.
"""
return [cls(statement, engine) for statement in split_kql(query)]
@classmethod
def _parse_statement(
cls,
statement: str,
engine: str,
) -> str:
if engine != "kustokql":
raise SupersetParseError(f"Invalid engine: {engine}")
statements = split_kql(statement)
if len(statements) != 1:
raise SupersetParseError("SQLStatement should have exactly one statement")
return statements[0].strip()
@classmethod
def _extract_tables_from_statement(cls, parsed: str, engine: str) -> set[Table]:
"""
Extract all tables referenced in the statement.
StormEvents
| where InjuriesDirect + InjuriesIndirect > 50
| join (PopulationData) on State
| project State, Population, TotalInjuries = InjuriesDirect + InjuriesIndirect
"""
logger.warning(
"Kusto KQL doesn't support table extraction. This means that data access "
"roles will not be enforced by Superset in the database."
)
return set()
def format(self, comments: bool = True) -> str:
"""
Pretty-format the SQL statement.
"""
return self._parsed
def get_settings(self) -> dict[str, str | bool]:
"""
Return the settings for the SQL statement.
>>> statement = KustoKQLStatement("set querytrace;")
>>> statement.get_settings()
{"querytrace": True}
"""
set_regex = r"^set\s+(?P<name>\w+)(?:\s*=\s*(?P<value>\w+))?$"
if match := re.match(set_regex, self._parsed, re.IGNORECASE):
return {match.group("name"): match.group("value") or True}
return {}
class SQLScript:
"""
A SQL script, with 0+ statements.
"""
# Special engines that can't be parsed using sqlglot. Supporting non-SQL engines
# adds a lot of complexity to Superset, so we should avoid adding new engines to
# this data structure.
special_engines = {
"kustokql": KustoKQLStatement,
}
def __init__(
self,
query: str,
engine: str,
):
statement_class = self.special_engines.get(engine, SQLStatement)
self.statements = statement_class.split_query(query, engine)
def format(self, comments: bool = True) -> str:
"""
Pretty-format the SQL query.
"""
return ";\n".join(statement.format(comments) for statement in self.statements)
def get_settings(self) -> dict[str, str | bool]:
"""
Return the settings for the SQL query.
>>> statement = SQLScript("SET foo = 'bar'; SET foo = 'baz'")
>>> statement.get_settings()
{"foo": "'baz'"}
"""
settings: dict[str, str | bool] = {}
for statement in self.statements:
settings.update(statement.get_settings())
return settings
class ParsedQuery:
def __init__(
self,
sql_statement: str,
strip_comments: bool = False,
engine: str | None = None,
):
if strip_comments:
sql_statement = sqlparse.format(sql_statement, strip_comments=True)
self.sql: str = sql_statement
self._dialect = SQLGLOT_DIALECTS.get(engine) if engine else None
self._tables: set[Table] = set()
self._alias_names: set[str] = set()
self._limit: int | None = None
logger.debug("Parsing with sqlparse statement: %s", self.sql)
self._parsed = sqlparse.parse(self.stripped())
for statement in self._parsed:
self._limit = _extract_limit_from_query(statement)
@property
def tables(self) -> set[Table]:
if not self._tables:
self._tables = self._extract_tables_from_sql()
return self._tables
def _extract_tables_from_sql(self) -> set[Table]:
"""
Extract all table references in a query.
Note: this uses sqlglot, since it's better at catching more edge cases.
"""
try:
statements = parse(self.stripped(), dialect=self._dialect)
except SqlglotError as ex:
logger.warning("Unable to parse SQL (%s): %s", self._dialect, self.sql)
message = (
"Error parsing near '{highlight}' at line {line}:{col}".format( # pylint: disable=consider-using-f-string
**ex.errors[0]
)
if isinstance(ex, ParseError)
else str(ex)
)
raise SupersetSecurityException(
SupersetError(
error_type=SupersetErrorType.QUERY_SECURITY_ACCESS_ERROR,
message=__(
"You may have an error in your SQL statement. {message}"
).format(message=message),
level=ErrorLevel.ERROR,
)
) from ex
return {
table
for statement in statements
for table in extract_tables_from_statement(statement, self._dialect)
if statement
}
def _extract_tables_from_statement(self, statement: exp.Expression) -> set[Table]:
"""
Extract all table references in a single statement.
Please not that this is not trivial; consider the following queries:
DESCRIBE some_table;
SHOW PARTITIONS FROM some_table;
WITH masked_name AS (SELECT * FROM some_table) SELECT * FROM masked_name;
See the unit tests for other tricky cases.
"""
sources: Iterable[exp.Table]
if isinstance(statement, exp.Describe):
# A `DESCRIBE` query has no sources in sqlglot, so we need to explicitly
# query for all tables.
sources = statement.find_all(exp.Table)
elif isinstance(statement, exp.Command):
# Commands, like `SHOW COLUMNS FROM foo`, have to be converted into a
# `SELECT` statetement in order to extract tables.
if not (literal := statement.find(exp.Literal)):
return set()
try:
pseudo_query = parse_one(
f"SELECT {literal.this}",
dialect=self._dialect,
)
sources = pseudo_query.find_all(exp.Table)
except SqlglotError:
return set()
else:
sources = [
source
for scope in traverse_scope(statement)
for source in scope.sources.values()
if isinstance(source, exp.Table) and not self._is_cte(source, scope)
]
return {
Table(
source.name,
source.db if source.db != "" else None,
source.catalog if source.catalog != "" else None,
)
for source in sources
}
def _is_cte(self, source: exp.Table, scope: Scope) -> bool:
"""
Is the source a CTE?
CTEs in the parent scope look like tables (and are represented by
exp.Table objects), but should not be considered as such;
otherwise a user with access to table `foo` could access any table
with a query like this:
WITH foo AS (SELECT * FROM target_table) SELECT * FROM foo
"""
parent_sources = scope.parent.sources if scope.parent else {}
ctes_in_scope = {
name
for name, parent_scope in parent_sources.items()
if isinstance(parent_scope, Scope)
and parent_scope.scope_type == ScopeType.CTE
}
return source.name in ctes_in_scope
@property
def limit(self) -> int | None:
return self._limit
def _get_cte_tables(self, parsed: dict[str, Any]) -> list[dict[str, Any]]:
if "with" not in parsed:
return []
return parsed["with"].get("cte_tables", [])
def _check_cte_is_select(self, oxide_parse: list[dict[str, Any]]) -> bool:
"""
Check if a oxide parsed CTE contains only SELECT statements
:param oxide_parse: parsed CTE
:return: True if CTE is a SELECT statement
"""
def is_body_select(body: dict[str, Any]) -> bool:
if op := body.get("SetOperation"):
return is_body_select(op["left"]) and is_body_select(op["right"])
return all(key == "Select" for key in body.keys())
for query in oxide_parse:
parsed_query = query["Query"]
cte_tables = self._get_cte_tables(parsed_query)
for cte_table in cte_tables:
is_select = is_body_select(cte_table["query"]["body"])
if not is_select:
return False
return True
def is_select(self) -> bool:
# make sure we strip comments; prevents a bug with comments in the CTE
parsed = sqlparse.parse(self.strip_comments())
seen_select = False
for statement in parsed:
# Check if this is a CTE
if statement.is_group and statement[0].ttype == Keyword.CTE:
if sqloxide_parse is not None:
try:
if not self._check_cte_is_select(
sqloxide_parse(self.strip_comments(), dialect="ansi")
):
return False
except ValueError:
# sqloxide was not able to parse the query, so let's continue with
# sqlparse
pass
inner_cte = self.get_inner_cte_expression(statement.tokens) or []
# Check if the inner CTE is a not a SELECT
if any(token.ttype == DDL for token in inner_cte) or any(
token.ttype == DML and token.normalized != "SELECT"
for token in inner_cte
):
return False
if statement.get_type() == "SELECT":
seen_select = True
continue
if statement.get_type() != "UNKNOWN":
return False
# for `UNKNOWN`, check all DDL/DML explicitly: only `SELECT` DML is allowed,
# and no DDL is allowed
if any(token.ttype == DDL for token in statement) or any(
token.ttype == DML and token.normalized != "SELECT"
for token in statement
):
return False
if imt(statement.tokens[0], m=(Keyword, "USE")):
continue
# return false on `EXPLAIN`, `SET`, `SHOW`, etc.
if imt(statement.tokens[0], t=Keyword):
return False
if not any(
token.ttype == DML and token.normalized == "SELECT"
for token in statement
):
return False
return seen_select
def get_inner_cte_expression(self, tokens: TokenList) -> TokenList | None:
for token in tokens:
if self._is_identifier(token):
for identifier_token in token.tokens:
if (
isinstance(identifier_token, Parenthesis)
and identifier_token.is_group
):
return identifier_token.tokens
return None
def is_valid_ctas(self) -> bool:
parsed = sqlparse.parse(self.strip_comments())
return parsed[-1].get_type() == "SELECT"
def is_valid_cvas(self) -> bool:
parsed = sqlparse.parse(self.strip_comments())
return len(parsed) == 1 and parsed[0].get_type() == "SELECT"
def is_explain(self) -> bool:
# Remove comments
statements_without_comments = sqlparse.format(
self.stripped(), strip_comments=True
)
# Explain statements will only be the first statement
return statements_without_comments.upper().startswith("EXPLAIN")
def is_show(self) -> bool:
# Remove comments
statements_without_comments = sqlparse.format(
self.stripped(), strip_comments=True
)
# Show statements will only be the first statement
return statements_without_comments.upper().startswith("SHOW")
def is_set(self) -> bool:
# Remove comments
statements_without_comments = sqlparse.format(
self.stripped(), strip_comments=True
)
# Set statements will only be the first statement
return statements_without_comments.upper().startswith("SET")
def is_unknown(self) -> bool:
return self._parsed[0].get_type() == "UNKNOWN"
def stripped(self) -> str:
return self.sql.strip(" \t\r\n;")
def strip_comments(self) -> str:
return sqlparse.format(self.stripped(), strip_comments=True)
def get_statements(self) -> list[str]:
"""Returns a list of SQL statements as strings, stripped"""
statements = []
for statement in self._parsed:
if statement:
sql = str(statement).strip(" \n;\t")
if sql:
statements.append(sql)
return statements
@staticmethod
def get_table(tlist: TokenList) -> Table | None:
"""
Return the table if valid, i.e., conforms to the [[catalog.]schema.]table
construct.
:param tlist: The SQL tokens
:returns: The table if the name conforms
"""
# Strip the alias if present.
idx = len(tlist.tokens)
if tlist.has_alias():
ws_idx, _ = tlist.token_next_by(t=Whitespace)
if ws_idx != -1:
idx = ws_idx
tokens = tlist.tokens[:idx]
if (
len(tokens) in (1, 3, 5)
and all(imt(token, t=[Name, String]) for token in tokens[::2])
and all(imt(token, m=(Punctuation, ".")) for token in tokens[1::2])
):
return Table(*[remove_quotes(token.value) for token in tokens[::-2]])
return None
@staticmethod
def _is_identifier(token: Token) -> bool:
return isinstance(token, (IdentifierList, Identifier))
def as_create_table(
self,
table_name: str,
schema_name: str | None = None,
overwrite: bool = False,
method: CtasMethod = CtasMethod.TABLE,
) -> str:
"""Reformats the query into the create table as query.
Works only for the single select SQL statements, in all other cases
the sql query is not modified.
:param table_name: table that will contain the results of the query execution
:param schema_name: schema name for the target table
:param overwrite: table_name will be dropped if true
:param method: method for the CTA query, currently view or table creation
:return: Create table as query
"""
exec_sql = ""
sql = self.stripped()
# TODO(bkyryliuk): quote full_table_name
full_table_name = f"{schema_name}.{table_name}" if schema_name else table_name
if overwrite:
exec_sql = f"DROP {method} IF EXISTS {full_table_name};\n"
exec_sql += f"CREATE {method} {full_table_name} AS \n{sql}"
return exec_sql
def set_or_update_query_limit(self, new_limit: int, force: bool = False) -> str:
"""Returns the query with the specified limit.
Does not change the underlying query if user did not apply the limit,
otherwise replaces the limit with the lower value between existing limit
in the query and new_limit.
:param new_limit: Limit to be incorporated into returned query
:return: The original query with new limit
"""
if not self._limit:
return f"{self.stripped()}\nLIMIT {new_limit}"
limit_pos = None
statement = self._parsed[0]
# Add all items to before_str until there is a limit
for pos, item in enumerate(statement.tokens):
if item.ttype in Keyword and item.value.lower() == "limit":
limit_pos = pos
break
_, limit = statement.token_next(idx=limit_pos)
# Override the limit only when it exceeds the configured value.
if limit.ttype == sqlparse.tokens.Literal.Number.Integer and (
force or new_limit < int(limit.value)
):
limit.value = new_limit
elif limit.is_group:
limit.value = f"{next(limit.get_identifiers())}, {new_limit}"
str_res = ""
for i in statement.tokens:
str_res += str(i.value)
return str_res
def sanitize_clause(clause: str) -> str:
# clause = sqlparse.format(clause, strip_comments=True)
statements = sqlparse.parse(clause)
if len(statements) != 1:
raise QueryClauseValidationException("Clause contains multiple statements")
open_parens = 0
previous_token = None
for token in statements[0]:
if token.value == "/" and previous_token and previous_token.value == "*":
raise QueryClauseValidationException("Closing unopened multiline comment")
if token.value == "*" and previous_token and previous_token.value == "/":
raise QueryClauseValidationException("Unclosed multiline comment")
if token.value in (")", "("):
open_parens += 1 if token.value == "(" else -1
if open_parens < 0:
raise QueryClauseValidationException(
"Closing unclosed parenthesis in filter clause"
)
previous_token = token
if open_parens > 0:
raise QueryClauseValidationException("Unclosed parenthesis in filter clause")
if previous_token and previous_token.ttype in Comment:
if previous_token.value[-1] != "\n":
clause = f"{clause}\n"
return clause
class InsertRLSState(StrEnum):
"""
State machine that scans for WHERE and ON clauses referencing tables.
"""
SCANNING = "SCANNING"
SEEN_SOURCE = "SEEN_SOURCE"
FOUND_TABLE = "FOUND_TABLE"
def has_table_query(token_list: TokenList) -> bool:
"""
Return if a statement has a query reading from a table.
>>> has_table_query(sqlparse.parse("COUNT(*)")[0])
False
>>> has_table_query(sqlparse.parse("SELECT * FROM table")[0])
True
Note that queries reading from constant values return false:
>>> has_table_query(sqlparse.parse("SELECT * FROM (SELECT 1)")[0])
False
"""
state = InsertRLSState.SCANNING
for token in token_list.tokens:
# Ignore comments
if isinstance(token, sqlparse.sql.Comment):
continue
# Recurse into child token list
if isinstance(token, TokenList) and has_table_query(token):
return True
# Found a source keyword (FROM/JOIN)
if imt(token, m=[(Keyword, "FROM"), (Keyword, "JOIN")]):
state = InsertRLSState.SEEN_SOURCE
# Found identifier/keyword after FROM/JOIN
elif state == InsertRLSState.SEEN_SOURCE and (
isinstance(token, sqlparse.sql.Identifier) or token.ttype == Keyword
):
return True
# Found nothing, leaving source
elif state == InsertRLSState.SEEN_SOURCE and token.ttype != Whitespace:
state = InsertRLSState.SCANNING
return False
def add_table_name(rls: TokenList, table: str) -> None:
"""
Modify a RLS expression inplace ensuring columns are fully qualified.
"""
tokens = rls.tokens[:]
while tokens:
token = tokens.pop(0)
if isinstance(token, Identifier) and token.get_parent_name() is None:
token.tokens = [
Token(Name, table),
Token(Punctuation, "."),
Token(Name, token.get_name()),
]
elif isinstance(token, TokenList):
tokens.extend(token.tokens)
def get_rls_for_table(
candidate: Token,
database_id: int,
default_schema: str | None,
) -> TokenList | None:
"""
Given a table name, return any associated RLS predicates.
"""
# pylint: disable=import-outside-toplevel
from superset import db
from superset.connectors.sqla.models import SqlaTable
if not isinstance(candidate, Identifier):
candidate = Identifier([Token(Name, candidate.value)])
table = ParsedQuery.get_table(candidate)
if not table:
return None
dataset = (
db.session.query(SqlaTable)
.filter(
and_(
SqlaTable.database_id == database_id,
SqlaTable.schema == (table.schema or default_schema),
SqlaTable.table_name == table.table,
)
)
.one_or_none()
)
if not dataset:
return None
template_processor = dataset.get_template_processor()
predicate = " AND ".join(
str(filter_)
for filter_ in dataset.get_sqla_row_level_filters(template_processor)
)
if not predicate:
return None
rls = sqlparse.parse(predicate)[0]
add_table_name(rls, table.table)
return rls
def insert_rls_as_subquery(
token_list: TokenList,
database_id: int,
default_schema: str | None,
) -> TokenList:
"""
Update a statement inplace applying any associated RLS predicates.
The RLS predicate is applied as subquery replacing the original table:
before: SELECT * FROM some_table WHERE 1=1
after: SELECT * FROM (
SELECT * FROM some_table WHERE some_table.id=42
) AS some_table
WHERE 1=1
This method is safer than ``insert_rls_in_predicate``, but doesn't work in all
databases.
"""
rls: TokenList | None = None
state = InsertRLSState.SCANNING
for token in token_list.tokens:
# Recurse into child token list
if isinstance(token, TokenList):
i = token_list.tokens.index(token)
token_list.tokens[i] = insert_rls_as_subquery(
token,
database_id,
default_schema,
)
# Found a source keyword (FROM/JOIN)
if imt(token, m=[(Keyword, "FROM"), (Keyword, "JOIN")]):
state = InsertRLSState.SEEN_SOURCE
# Found identifier/keyword after FROM/JOIN, test for table
elif state == InsertRLSState.SEEN_SOURCE and (
isinstance(token, Identifier) or token.ttype == Keyword
):
rls = get_rls_for_table(token, database_id, default_schema)
if rls:
# replace table with subquery
subquery_alias = (
token.tokens[-1].value
if isinstance(token, Identifier)
else token.value
)
i = token_list.tokens.index(token)
# strip alias from table name
if isinstance(token, Identifier) and token.has_alias():
whitespace_index = token.token_next_by(t=Whitespace)[0]
token.tokens = token.tokens[:whitespace_index]
token_list.tokens[i] = Identifier(
[
Parenthesis(
[
Token(Punctuation, "("),
Token(DML, "SELECT"),
Token(Whitespace, " "),
Token(Wildcard, "*"),
Token(Whitespace, " "),
Token(Keyword, "FROM"),
Token(Whitespace, " "),
token,
Token(Whitespace, " "),
Where(
[
Token(Keyword, "WHERE"),
Token(Whitespace, " "),
rls,
]
),
Token(Punctuation, ")"),
]
),
Token(Whitespace, " "),
Token(Keyword, "AS"),
Token(Whitespace, " "),
Identifier([Token(Name, subquery_alias)]),
]
)
state = InsertRLSState.SCANNING
# Found nothing, leaving source
elif state == InsertRLSState.SEEN_SOURCE and token.ttype != Whitespace:
state = InsertRLSState.SCANNING
return token_list
def insert_rls_in_predicate(
token_list: TokenList,
database_id: int,
default_schema: str | None,
) -> TokenList:
"""
Update a statement inplace applying any associated RLS predicates.
The RLS predicate is ``AND``ed to any existing predicates:
before: SELECT * FROM some_table WHERE 1=1
after: SELECT * FROM some_table WHERE ( 1=1) AND some_table.id=42
"""
rls: TokenList | None = None
state = InsertRLSState.SCANNING
for token in token_list.tokens:
# Recurse into child token list
if isinstance(token, TokenList):
i = token_list.tokens.index(token)
token_list.tokens[i] = insert_rls_in_predicate(
token,
database_id,
default_schema,
)
# Found a source keyword (FROM/JOIN)
if imt(token, m=[(Keyword, "FROM"), (Keyword, "JOIN")]):
state = InsertRLSState.SEEN_SOURCE
# Found identifier/keyword after FROM/JOIN, test for table
elif state == InsertRLSState.SEEN_SOURCE and (
isinstance(token, Identifier) or token.ttype == Keyword
):
rls = get_rls_for_table(token, database_id, default_schema)
if rls:
state = InsertRLSState.FOUND_TABLE
# Found WHERE clause, insert RLS. Note that we insert it even it already exists,
# to be on the safe side: it could be present in a clause like `1=1 OR RLS`.
elif state == InsertRLSState.FOUND_TABLE and isinstance(token, Where):
rls = cast(TokenList, rls)
token.tokens[1:1] = [Token(Whitespace, " "), Token(Punctuation, "(")]
token.tokens.extend(
[
Token(Punctuation, ")"),
Token(Whitespace, " "),
Token(Keyword, "AND"),
Token(Whitespace, " "),
]
+ rls.tokens
)
state = InsertRLSState.SCANNING
# Found ON clause, insert RLS. The logic for ON is more complicated than the logic
# for WHERE because in the former the comparisons are siblings, while on the
# latter they are children.
elif (
state == InsertRLSState.FOUND_TABLE
and token.ttype == Keyword
and token.value.upper() == "ON"
):
tokens = [
Token(Whitespace, " "),
rls,
Token(Whitespace, " "),
Token(Keyword, "AND"),
Token(Whitespace, " "),
Token(Punctuation, "("),
]
i = token_list.tokens.index(token)
token.parent.tokens[i + 1 : i + 1] = tokens
i += len(tokens) + 2
# close parenthesis after last existing comparison
j = 0
for j, sibling in enumerate(token_list.tokens[i:]):
# scan until we hit a non-comparison keyword (like ORDER BY) or a WHERE
if (
sibling.ttype == Keyword
and not imt(
sibling, m=[(Keyword, "AND"), (Keyword, "OR"), (Keyword, "NOT")]
)
or isinstance(sibling, Where)
):
j -= 1
break
token.parent.tokens[i + j + 1 : i + j + 1] = [
Token(Whitespace, " "),
Token(Punctuation, ")"),
Token(Whitespace, " "),
]
state = InsertRLSState.SCANNING
# Found table but no WHERE clause found, insert one
elif state == InsertRLSState.FOUND_TABLE and token.ttype != Whitespace:
i = token_list.tokens.index(token)
token_list.tokens[i:i] = [
Token(Whitespace, " "),
Where([Token(Keyword, "WHERE"), Token(Whitespace, " "), rls]),
Token(Whitespace, " "),
]
state = InsertRLSState.SCANNING
# Found nothing, leaving source
elif state == InsertRLSState.SEEN_SOURCE and token.ttype != Whitespace:
state = InsertRLSState.SCANNING
# found table at the end of the statement; append a WHERE clause
if state == InsertRLSState.FOUND_TABLE:
token_list.tokens.extend(
[
Token(Whitespace, " "),
Where([Token(Keyword, "WHERE"), Token(Whitespace, " "), rls]),
]
)
return token_list
# mapping between sqloxide and SQLAlchemy dialects
SQLOXIDE_DIALECTS = {
"ansi": {"trino", "trinonative", "presto"},
"hive": {"hive", "databricks"},
"ms": {"mssql"},
"mysql": {"mysql"},
"postgres": {
"cockroachdb",
"hana",
"netezza",
"postgres",
"postgresql",
"redshift",
"vertica",
},
"snowflake": {"snowflake"},
"sqlite": {"sqlite", "gsheets", "shillelagh"},
"clickhouse": {"clickhouse"},
}
RE_JINJA_VAR = re.compile(r"\{\{[^\{\}]+\}\}")
RE_JINJA_BLOCK = re.compile(r"\{[%#][^\{\}%#]+[%#]\}")
def extract_table_references(
sql_text: str, sqla_dialect: str, show_warning: bool = True
) -> set[Table]:
"""
Return all the dependencies from a SQL sql_text.
"""
dialect = "generic"
tree = None
if sqloxide_parse:
for dialect, sqla_dialects in SQLOXIDE_DIALECTS.items():
if sqla_dialect in sqla_dialects:
break
sql_text = RE_JINJA_BLOCK.sub(" ", sql_text)
sql_text = RE_JINJA_VAR.sub("abc", sql_text)
try:
tree = sqloxide_parse(sql_text, dialect=dialect)
except Exception as ex: # pylint: disable=broad-except
if show_warning:
logger.warning(
"\nUnable to parse query with sqloxide:\n%s\n%s", sql_text, ex
)
# fallback to sqlparse
if not tree:
parsed = ParsedQuery(sql_text)
return parsed.tables
def find_nodes_by_key(element: Any, target: str) -> Iterator[Any]:
"""
Find all nodes in a SQL tree matching a given key.
"""
if isinstance(element, list):
for child in element:
yield from find_nodes_by_key(child, target)
elif isinstance(element, dict):
for key, value in element.items():
if key == target:
yield value
else:
yield from find_nodes_by_key(value, target)
return {
Table(*[part["value"] for part in table["name"][::-1]])
for table in find_nodes_by_key(tree, "Table")
}
def extract_tables_from_jinja_sql(sql: str, database: Database) -> set[Table]:
"""
Extract all table references in the Jinjafied SQL statement.
Due to Jinja templating, a multiphase approach is necessary as the Jinjafied SQL
statement may represent invalid SQL which is non-parsable by SQLGlot.
Firstly, we extract any tables referenced within the confines of specific Jinja
macros. Secondly, we replace these non-SQL Jinja calls with a pseudo-benign SQL
expression to help ensure that the resulting SQL statements are parsable by
SQLGlot.
:param sql: The Jinjafied SQL statement
:param database: The database associated with the SQL statement
:returns: The set of tables referenced in the SQL statement
:raises SupersetSecurityException: If SQLGlot is unable to parse the SQL statement
:raises jinja2.exceptions.TemplateError: If the Jinjafied SQL could not be rendered
"""
from superset.jinja_context import ( # pylint: disable=import-outside-toplevel
get_template_processor,
)
processor = get_template_processor(database)
template = processor.env.parse(sql)
tables = set()
for node in template.find_all(nodes.Call):
if isinstance(node.node, nodes.Getattr) and node.node.attr in (
"latest_partition",
"latest_sub_partition",
):
# Try to extract the table referenced in the macro.
try:
tables.add(
Table(
*[
remove_quotes(part.strip())
for part in node.args[0].as_const().split(".")[::-1]
if len(node.args) == 1
]
)
)
except nodes.Impossible:
pass
# Replace the potentially problematic Jinja macro with some benign SQL.
node.__class__ = nodes.TemplateData
node.fields = nodes.TemplateData.fields
node.data = "NULL"
return (
tables
| ParsedQuery(
sql_statement=processor.process_template(template),
engine=database.db_engine_spec.engine,
).tables
)