Files
d19ef5e0be refactor(driver): accept None for port and database as 'not specified' (#813)
* refactor(driver): accept None for port and database as canonical 'not specified'

* docs: track internal driver signature default change

* keep legacy port and database sentinels working

* allow trailing slash

---------

Co-authored-by: Joe S <[email protected]>
2026-06-23 15:27:25 -07:00

1280 lines
57 KiB
Python

from __future__ import annotations
import io
import logging
from abc import ABC, abstractmethod
from collections.abc import Generator, Sequence
from datetime import timezone, tzinfo
from typing import (
TYPE_CHECKING,
Any,
BinaryIO,
cast,
)
from zoneinfo import ZoneInfoNotFoundError
from clickhouse_connect import common
from clickhouse_connect.common import version
from clickhouse_connect.datatypes import dynamic as dynamic_module
from clickhouse_connect.datatypes.base import ClickHouseType
from clickhouse_connect.datatypes.registry import get_from_name
from clickhouse_connect.driver import options, tzutil
from clickhouse_connect.driver.binding import quote_identifier
from clickhouse_connect.driver.common import (
StreamContext,
coerce_bool,
coerce_int,
dict_copy,
)
from clickhouse_connect.driver.constants import (
CH_VERSION_WITH_PROTOCOL,
PROTOCOL_VERSION_WITH_LOW_CARD,
)
from clickhouse_connect.driver.exceptions import (
DataError,
OperationalError,
ProgrammingError,
)
from clickhouse_connect.driver.external import ExternalData
from clickhouse_connect.driver.insert import InsertContext
from clickhouse_connect.driver.models import ColumnDef, SettingDef, SettingStatus
from clickhouse_connect.driver.options import (
check_arrow,
check_numpy,
check_pandas,
check_polars,
)
from clickhouse_connect.driver.query import (
_VALID_TZ_MODES,
_VALID_TZ_SOURCES,
QueryContext,
QueryResult,
TzMode,
TzSource,
arrow_buffer,
to_arrow,
to_arrow_batches,
)
from clickhouse_connect.driver.summary import QuerySummary
from clickhouse_connect.driver.types import Closable
if TYPE_CHECKING:
import numpy
import pandas
import polars
import pyarrow
io.DEFAULT_BUFFER_SIZE = 1024 * 256 # type: ignore[misc] # override module default buffer size
logger = logging.getLogger(__name__)
arrow_str_setting = "output_format_arrow_string_as_string"
def _strip_utc_timezone_from_arrow(table: pyarrow.Table) -> pyarrow.Table:
"""Strip UTC timezone from timestamp columns in Arrow table.
This ensures naive datetimes are returned when the server timezone is UTC
and tz_mode is 'naive_utc' (the default).
Only UTC-equivalent timezones (UTC, Etc/UTC, GMT, etc.) are stripped.
Non-UTC timezones carry important offset information and are always
preserved regardless of tz_mode setting.
"""
new_fields = []
needs_cast = False
for field in table.schema:
if options.arrow.types.is_timestamp(field.type) and tzutil.is_utc_timezone(field.type.tz):
new_fields.append(options.arrow.field(field.name, options.arrow.timestamp(field.type.unit)))
needs_cast = True
else:
new_fields.append(field)
if needs_cast:
return table.cast(options.arrow.schema(new_fields))
return table
def _apply_arrow_tz_policy(table: pyarrow.Table, tz_mode: str) -> pyarrow.Table:
"""Apply the tz_mode policy to an Arrow table before conversion.
Handles UTC stripping when tz_mode is "naive_utc" and warns when
tz_mode is "schema" since that mode is not yet implemented for
Arrow-based queries.
"""
if tz_mode == "schema":
logger.warning(
'tz_mode="schema" is not yet supported for Arrow-based query methods. '
"It would require a separate schema lookup since ClickHouse attaches the server "
"timezone to all DateTime columns in Arrow format. Use query/query_df for "
"schema-matching behavior or open an issue if you need Arrow support."
)
if tz_mode == "naive_utc":
table = _strip_utc_timezone_from_arrow(table)
return table
class Client(ABC):
"""
Base ClickHouse Connect client
"""
compression: str | None = None
write_compression: str | None = None
protocol_version = 0
valid_transport_settings: set[str] = set()
optional_transport_settings: set[str] = set()
database = None
max_error_message = 0
_tz_source: TzSource = "auto"
_apply_server_tz = False
tz_mode: TzMode = "naive_utc"
show_clickhouse_errors = True
@property
def tz_source(self) -> TzSource:
return self._tz_source
@tz_source.setter
def tz_source(self, value: TzSource):
if value not in _VALID_TZ_SOURCES:
raise ProgrammingError(f'tz_source must be "auto", "server", or "local", got "{value}"')
self._tz_source = value
if value == "auto":
self._apply_server_tz = self._dst_safe
else:
self._apply_server_tz = value == "server"
def __init__(
self,
database: str | None,
query_limit: int,
uri: str,
query_retries: int,
server_host_name: str | None,
tz_source: TzSource | None = None,
tz_mode: TzMode | None = None,
show_clickhouse_errors: bool | None = None,
autoconnect: bool = True,
):
"""
Shared initialization of ClickHouse Connect client
:param database: database name
:param query_limit: default LIMIT for queries
:param uri: uri for error messages
:param tz_source: Controls how the client determines the fallback timezone for DateTime columns without an
explicit timezone. "auto" (default) auto-detects based on DST safety of server timezone. "server" always
uses the server timezone. "local" always uses the local timezone.
:param tz_mode: Controls timezone-aware behavior for UTC DateTime columns. "naive_utc" (default) returns
naive UTC timestamps. "aware" forces timezone-aware UTC datetimes. "schema" returns datetimes that
match the server's column definition which means timezone-aware when the column defines a timezone and naive
for bare DateTime columns.
:param autoconnect: If True, immediately connect to server and fetch settings. If False,
defer connection to _connect() method. Used by async clients to avoid blocking I/O in __init__.
"""
self.query_limit = coerce_int(query_limit)
self.query_retries = coerce_int(query_retries)
if database and database != "__default__":
self.database = database
if show_clickhouse_errors is not None:
self.show_clickhouse_errors = coerce_bool(show_clickhouse_errors)
self.server_host_name = server_host_name
self.uri = uri
self.tz_mode = tz_mode if tz_mode is not None else "naive_utc"
if self.tz_mode not in _VALID_TZ_MODES:
raise ProgrammingError(f'tz_mode must be "naive_utc", "aware", or "schema", got "{self.tz_mode}"')
resolved_tz_source = tz_source if tz_source is not None else "auto"
if resolved_tz_source not in _VALID_TZ_SOURCES:
raise ProgrammingError(f'tz_source must be "auto", "server", or "local", got "{resolved_tz_source}"')
self._tz_source = resolved_tz_source
# Initialize attributes that will be set during connection
self.server_version: str | None = None
self.server_tz: tzinfo = timezone.utc
self.server_settings: dict[str, SettingDef] = {}
if autoconnect:
self._init_common_settings(resolved_tz_source)
else:
# Store for deferred async initialization
self._deferred_tz_source = resolved_tz_source
def _init_common_settings(self, tz_source: TzSource):
self.server_tz, self._dst_safe = timezone.utc, True
version_result = self.command("SELECT version(), timezone()", use_database=False)
if not isinstance(version_result, Sequence) or isinstance(version_result, str):
raise OperationalError(f"Unexpected response to server version query: {version_result!r}")
self.server_version, server_tz = version_result[0], version_result[1]
try:
server_tz_info = tzutil.resolve_zone(server_tz)
server_tz_info, self._dst_safe = tzutil.normalize_timezone(server_tz_info, trust_fixed_offset=True)
self.server_tz = server_tz_info
except ZoneInfoNotFoundError:
logger.warning(
"Server timezone %s could not be resolved, falling back to UTC; %s",
server_tz,
tzutil.TZDATA_HINT,
)
if tz_source == "auto":
self._apply_server_tz = self._dst_safe
else:
self._apply_server_tz = tz_source == "server"
if not self._apply_server_tz and not tzutil.local_tz_dst_safe:
logger.warning(
"local timezone %s may return unexpected times due to Daylight Savings Time/" + "Summer Time differences",
tzutil.local_tz.tzname(None),
)
readonly = "readonly"
if not self.min_version("19.17"):
readonly = common.get_setting("readonly")
server_settings = self.query(f"SELECT name, value, {readonly} as readonly FROM system.settings LIMIT 10000")
self.server_settings = {row["name"]: SettingDef(**row) for row in server_settings.named_results()}
if self.min_version(CH_VERSION_WITH_PROTOCOL) and common.get_setting("use_protocol_version"):
# Unfortunately we have to validate that the client protocol version is actually used by ClickHouse
# since the query parameter could be stripped off (in particular, by CHProxy)
test_data = self.raw_query(
"SELECT 1 AS check", fmt="Native", settings={"client_protocol_version": PROTOCOL_VERSION_WITH_LOW_CARD}
)
if test_data[8:16] == b"\x01\x01\x05check":
self.protocol_version = PROTOCOL_VERSION_WITH_LOW_CARD
if self._setting_status("date_time_input_format").is_writable:
self.set_client_setting("date_time_input_format", "best_effort")
if (
self._setting_status("allow_experimental_json_type").is_set
and self._setting_status("cast_string_to_dynamic_use_inference").is_writable
):
self.set_client_setting("cast_string_to_dynamic_use_inference", "1")
if self.min_version("24.8") and not self.min_version("24.10"):
dynamic_module.json_serialization_format = 0
def _validate_settings(self, settings: dict[str, Any] | None) -> dict[str, str]:
"""
This strips any ClickHouse settings that are not recognized or are read only.
:param settings: Dictionary of setting name and values
:return: A filtered dictionary of settings with values rendered as strings
"""
validated: dict[str, str] = {}
invalid_action = common.get_setting("invalid_setting_action")
if not settings:
return validated
for key, value in settings.items():
str_value = self._validate_setting(key, value, invalid_action)
if str_value is not None:
validated[key] = value
return validated
def _validate_setting(self, key: str, value: Any, invalid_action: str) -> str | None:
str_value = str(value)
if value is True:
str_value = "1"
elif value is False:
str_value = "0"
if key not in self.valid_transport_settings:
setting_def = self.server_settings.get(key)
current_setting = self.get_client_setting(key)
# Skip if the requested value matches the server's value and either the setting
# is readonly i.e. there's nothing to change or already explicitly stored on the client
if setting_def and setting_def.value == str_value:
if setting_def.readonly or (current_setting is not None and current_setting == setting_def.value):
return None
if setting_def is None or setting_def.readonly:
if key in self.optional_transport_settings:
return None
if invalid_action == "send":
logger.warning("Attempting to send unrecognized or readonly setting %s", key)
elif invalid_action == "drop":
logger.warning("Dropping unrecognized or readonly settings %s", key)
return None
else:
raise ProgrammingError(f"Setting {key} is unknown or readonly") from None
return str_value
def _setting_status(self, key: str) -> SettingStatus:
comp_setting = self.server_settings.get(key)
if not comp_setting:
return SettingStatus(False, False)
return SettingStatus(comp_setting.value != "0", comp_setting.readonly != 1)
def _prep_query(self, context: QueryContext):
if context.is_select and not context.has_limit and self.query_limit:
limit = f"\n LIMIT {self.query_limit}"
if isinstance(context.query, bytes):
return context.final_query + limit.encode()
return context.final_query + limit
return context.final_query
def _check_tz_change(self, new_tz) -> tzinfo | None:
if new_tz:
try:
new_tzinfo = tzutil.resolve_zone(new_tz)
if new_tzinfo != self.server_tz:
return new_tzinfo
except ZoneInfoNotFoundError:
logger.warning(
"Unrecognized timezone %s received from ClickHouse; %s",
new_tz,
tzutil.TZDATA_HINT,
)
return None
@abstractmethod
def _query_with_context(self, context: QueryContext) -> QueryResult:
pass
@abstractmethod
def set_client_setting(self, key: str, value: Any) -> None:
"""
Set a clickhouse setting for the client after initialization. If a setting is not recognized by ClickHouse,
or the setting is identified as "read_only", this call will either throw a Programming exception or attempt
to send the setting anyway based on the common setting 'invalid_setting_action'
:param key: ClickHouse setting name
:param value: ClickHouse setting value
"""
@abstractmethod
def get_client_setting(self, key: str) -> str | None:
"""
:param key: The setting key
:return: The string value of the setting, if it exists, or None
"""
@abstractmethod
def set_access_token(self, access_token: str) -> None:
"""
Set the ClickHouse access token for the client
:param access_token: Access token string
"""
def query(
self,
query: str | None = None,
parameters: Sequence | dict[str, Any] | None = None,
settings: dict[str, Any] | None = None,
query_formats: dict[str, str] | None = None,
column_formats: dict[str, str | dict[str, str]] | None = None,
encoding: str | None = None,
use_none: bool | None = None,
column_oriented: bool | None = None,
use_numpy: bool | None = None,
max_str_len: int | None = None,
context: QueryContext | None = None,
query_tz: str | tzinfo | None = None,
column_tzs: dict[str, str | tzinfo] | None = None,
external_data: ExternalData | None = None,
transport_settings: dict[str, str] | None = None,
tz_mode: TzMode | None = None,
) -> QueryResult:
"""
Main query method for SELECT, DESCRIBE and other SQL statements that return a result matrix. For
parameters, see the create_query_context method
:return: QueryResult -- data and metadata from response
"""
if query and query.lower().strip().startswith("select __connect_version__"):
return QueryResult(
[[f"ClickHouse Connect v.{version()} â“’ ClickHouse Inc."]],
None,
("connect_version",),
(get_from_name("String"),),
)
kwargs = locals().copy()
del kwargs["self"]
query_context = self.create_query_context(**kwargs)
if query_context.is_command:
response = self.command(
cast(str, query),
parameters=query_context.parameters,
settings=query_context.settings,
external_data=query_context.external_data,
transport_settings=query_context.transport_settings,
)
if isinstance(response, QuerySummary):
return response.as_query_result()
return QueryResult([response] if isinstance(response, list) else [[response]])
return self._query_with_context(query_context)
def query_column_block_stream(
self,
query: str | None = None,
parameters: Sequence | dict[str, Any] | None = None,
settings: dict[str, Any] | None = None,
query_formats: dict[str, str] | None = None,
column_formats: dict[str, str | dict[str, str]] | None = None,
encoding: str | None = None,
use_none: bool | None = None,
context: QueryContext | None = None,
query_tz: str | tzinfo | None = None,
column_tzs: dict[str, str | tzinfo] | None = None,
external_data: ExternalData | None = None,
transport_settings: dict[str, str] | None = None,
tz_mode: TzMode | None = None,
) -> StreamContext:
"""
Variation of main query method that returns a stream of column oriented blocks. For
parameters, see the create_query_context method.
:return: StreamContext -- Iterable stream context that returns column oriented blocks
"""
return self._context_query(locals(), use_numpy=False, streaming=True).column_block_stream
def query_row_block_stream(
self,
query: str | None = None,
parameters: Sequence | dict[str, Any] | None = None,
settings: dict[str, Any] | None = None,
query_formats: dict[str, str] | None = None,
column_formats: dict[str, str | dict[str, str]] | None = None,
encoding: str | None = None,
use_none: bool | None = None,
context: QueryContext | None = None,
query_tz: str | tzinfo | None = None,
column_tzs: dict[str, str | tzinfo] | None = None,
external_data: ExternalData | None = None,
transport_settings: dict[str, str] | None = None,
tz_mode: TzMode | None = None,
) -> StreamContext:
"""
Variation of main query method that returns a stream of row oriented blocks. For
parameters, see the create_query_context method.
:return: StreamContext -- Iterable stream context that returns blocks of rows
"""
return self._context_query(locals(), use_numpy=False, streaming=True).row_block_stream
def query_rows_stream(
self,
query: str | None = None,
parameters: Sequence | dict[str, Any] | None = None,
settings: dict[str, Any] | None = None,
query_formats: dict[str, str] | None = None,
column_formats: dict[str, str | dict[str, str]] | None = None,
encoding: str | None = None,
use_none: bool | None = None,
context: QueryContext | None = None,
query_tz: str | tzinfo | None = None,
column_tzs: dict[str, str | tzinfo] | None = None,
external_data: ExternalData | None = None,
transport_settings: dict[str, str] | None = None,
tz_mode: TzMode | None = None,
) -> StreamContext:
"""
Variation of main query method that returns a stream of row oriented blocks. For
parameters, see the create_query_context method.
:return: StreamContext -- Iterable stream context that returns blocks of rows
"""
return self._context_query(locals(), use_numpy=False, streaming=True).rows_stream
@abstractmethod
def raw_query(
self,
query: str,
parameters: Sequence | dict[str, Any] | None = None,
settings: dict[str, Any] | None = None,
fmt: str | None = None,
use_database: bool = True,
external_data: ExternalData | None = None,
transport_settings: dict[str, str] | None = None,
) -> bytes:
"""
Query method that simply returns the raw ClickHouse format bytes
:param query: Query statement/format string
:param parameters: Optional dictionary used to format the query
:param settings: Optional dictionary of ClickHouse settings (key/string values)
:param fmt: ClickHouse output format
:param use_database: Send the database parameter to ClickHouse so the command will be executed in the client
database context.
:param external_data: External data to send with the query
:param transport_settings: Optional dictionary of transport level settings (HTTP headers, etc.)
:return: bytes representing raw ClickHouse return value based on format
"""
@abstractmethod
def raw_stream(
self,
query: str,
parameters: Sequence | dict[str, Any] | None = None,
settings: dict[str, Any] | None = None,
fmt: str | None = None,
use_database: bool = True,
external_data: ExternalData | None = None,
transport_settings: dict[str, str] | None = None,
) -> io.IOBase | StreamContext:
"""
Query method that returns the result as a stream iterator.
:param query: Query statement/format string
:param parameters: Optional dictionary used to format the query
:param settings: Optional dictionary of ClickHouse settings (key/string values)
:param fmt: ClickHouse output format
:param use_database Send the database parameter to ClickHouse so the command will be executed in the client
database context.
:param external_data: External data to send with the query.
:param transport_settings: Optional dictionary of transport level settings (HTTP headers, etc.)
:return: io.IOBase (sync) or StreamContext (async) - both support iteration over raw bytes
"""
def query_np(
self,
query: str | None = None,
parameters: Sequence | dict[str, Any] | None = None,
settings: dict[str, Any] | None = None,
query_formats: dict[str, str] | None = None,
column_formats: dict[str, str] | None = None,
encoding: str | None = None,
use_none: bool | None = None,
max_str_len: int | None = None,
context: QueryContext | None = None,
external_data: ExternalData | None = None,
transport_settings: dict[str, str] | None = None,
) -> numpy.ndarray:
"""
Query method that returns the results as a numpy array. For parameter values, see the
create_query_context method
:return: Numpy array representing the result set
"""
check_numpy()
self._add_integration_tag("numpy")
return self._context_query(locals(), use_numpy=True).np_result
def query_np_stream(
self,
query: str | None = None,
parameters: Sequence | dict[str, Any] | None = None,
settings: dict[str, Any] | None = None,
query_formats: dict[str, str] | None = None,
column_formats: dict[str, str] | None = None,
encoding: str | None = None,
use_none: bool | None = None,
max_str_len: int | None = None,
context: QueryContext | None = None,
external_data: ExternalData | None = None,
transport_settings: dict[str, str] | None = None,
) -> StreamContext:
"""
Query method that returns the results as a stream of numpy arrays. For parameter values, see the
create_query_context method
:return: Generator that yield a numpy array per block representing the result set
"""
check_numpy()
self._add_integration_tag("numpy")
return self._context_query(locals(), use_numpy=True, streaming=True).np_stream
def query_df(
self,
query: str | None = None,
parameters: Sequence | dict[str, Any] | None = None,
settings: dict[str, Any] | None = None,
query_formats: dict[str, str] | None = None,
column_formats: dict[str, str] | None = None,
encoding: str | None = None,
use_none: bool | None = None,
max_str_len: int | None = None,
use_na_values: bool | None = None,
query_tz: str | None = None,
column_tzs: dict[str, str | tzinfo] | None = None,
context: QueryContext | None = None,
external_data: ExternalData | None = None,
use_extended_dtypes: bool | None = None,
transport_settings: dict[str, str] | None = None,
tz_mode: TzMode | None = None,
) -> pandas.DataFrame:
"""
Query method that results the results as a pandas dataframe. For parameter values, see the
create_query_context method
:return: Pandas dataframe representing the result set
"""
check_pandas()
self._add_integration_tag("pandas")
return self._context_query(locals(), use_numpy=True, as_pandas=True).df_result
def query_df_stream(
self,
query: str | None = None,
parameters: Sequence | dict[str, Any] | None = None,
settings: dict[str, Any] | None = None,
query_formats: dict[str, str] | None = None,
column_formats: dict[str, str] | None = None,
encoding: str | None = None,
use_none: bool | None = None,
max_str_len: int | None = None,
use_na_values: bool | None = None,
query_tz: str | None = None,
column_tzs: dict[str, str | tzinfo] | None = None,
context: QueryContext | None = None,
external_data: ExternalData | None = None,
use_extended_dtypes: bool | None = None,
transport_settings: dict[str, str] | None = None,
tz_mode: TzMode | None = None,
) -> StreamContext:
"""
Query method that returns the results as a StreamContext. For parameter values, see the
create_query_context method
:return: Generator that yields a Pandas dataframe per block representing the result set
"""
check_pandas()
self._add_integration_tag("pandas")
return self._context_query(locals(), use_numpy=True, as_pandas=True, streaming=True).df_stream
def create_query_context(
self,
query: str | bytes | None = None,
parameters: Sequence | dict[str, Any] | None = None,
settings: dict[str, Any] | None = None,
query_formats: dict[str, str] | None = None,
column_formats: dict[str, str | dict[str, str]] | None = None,
encoding: str | None = None,
use_none: bool | None = None,
column_oriented: bool | None = None,
use_numpy: bool | None = False,
max_str_len: int | None = 0,
context: QueryContext | None = None,
query_tz: str | tzinfo | None = None,
column_tzs: dict[str, str | tzinfo] | None = None,
use_na_values: bool | None = None,
streaming: bool = False,
as_pandas: bool = False,
external_data: ExternalData | None = None,
use_extended_dtypes: bool | None = None,
transport_settings: dict[str, str] | None = None,
tz_mode: TzMode | None = None,
) -> QueryContext:
"""
Creates or updates a reusable QueryContext object
:param query: Query statement/format string
:param parameters: Optional dictionary used to format the query
:param settings: Optional dictionary of ClickHouse settings (key/string values)
:param query_formats: See QueryContext __init__ docstring
:param column_formats: See QueryContext __init__ docstring
:param encoding: See QueryContext __init__ docstring
:param use_none: Use None for ClickHouse NULL instead of default values. Note that using None in Numpy
arrays will force the numpy array dtype to 'object', which is often inefficient. This effect also
will impact the performance of Pandas dataframes.
:param column_oriented: Deprecated. Controls orientation of the QueryResult result_set property
:param use_numpy: Return QueryResult columns as one-dimensional numpy arrays
:param max_str_len: Limit returned ClickHouse String values to this length, which allows a Numpy
structured array even with ClickHouse variable length String columns. If 0, Numpy arrays for
String columns will always be object arrays
:param context: An existing QueryContext to be updated with any provided parameter values
:param query_tz: Either a string IANA timezone name or a tzinfo object (strings are resolved via zoneinfo).
Values for any DateTime or DateTime64 column in the query will be converted to Python datetime.datetime
objects with the selected timezone.
:param column_tzs: A dictionary of column names to tzinfo objects (or strings that will be converted to
tzinfo objects). The timezone will be applied to datetime objects returned in the query
:param tz_mode: Override the client default for handling UTC results. "aware" forces timezone-aware
UTC datetimes, "naive_utc" returns naive UTC datetimes, and "schema" returns datetimes matching the
server's column definition.
:param use_na_values: Deprecated alias for use_advanced_dtypes
:param as_pandas Return the result columns as pandas.Series objects
:param streaming Marker used to correctly configure streaming queries
:param external_data ClickHouse "external data" to send with query
:param use_extended_dtypes: Only relevant to Pandas Dataframe queries. Use Pandas "missing types", such as
pandas.NA and pandas.NaT for ClickHouse NULL values, as well as extended Pandas dtypes such as IntegerArray
and StringArray. Defaulted to True for query_df methods
:param transport_settings: Optional dictionary of transport level settings (HTTP headers, etc.)
:return: Reusable QueryContext
"""
resolved_tz_mode = tz_mode if tz_mode is not None else self.tz_mode
if context:
return context.updated_copy(
query=query,
parameters=parameters,
settings=settings,
query_formats=query_formats,
column_formats=column_formats,
encoding=encoding,
server_tz=self.server_tz,
use_none=use_none,
column_oriented=column_oriented,
use_numpy=use_numpy,
max_str_len=max_str_len,
query_tz=query_tz,
column_tzs=column_tzs,
tz_mode=resolved_tz_mode,
as_pandas=as_pandas,
use_extended_dtypes=use_extended_dtypes,
streaming=streaming,
external_data=external_data,
transport_settings=transport_settings,
)
if use_numpy and max_str_len is None:
max_str_len = 0
if use_extended_dtypes is None:
use_extended_dtypes = use_na_values
if as_pandas and use_extended_dtypes is None:
use_extended_dtypes = True
return QueryContext(
query=cast(str | bytes, query),
parameters=parameters,
settings=settings,
query_formats=query_formats,
column_formats=column_formats,
encoding=encoding,
server_tz=self.server_tz,
use_none=use_none,
column_oriented=column_oriented,
use_numpy=use_numpy,
max_str_len=max_str_len,
query_tz=query_tz,
column_tzs=column_tzs,
tz_mode=resolved_tz_mode,
use_extended_dtypes=use_extended_dtypes,
as_pandas=as_pandas,
streaming=streaming,
apply_server_tz=self._apply_server_tz,
external_data=external_data,
transport_settings=transport_settings,
)
def query_arrow(
self,
query: str,
parameters: Sequence | dict[str, Any] | None = None,
settings: dict[str, Any] | None = None,
use_strings: bool | None = None,
external_data: ExternalData | None = None,
transport_settings: dict[str, str] | None = None,
) -> pyarrow.Table:
"""
Query method using the ClickHouse Arrow format to return a PyArrow table
:param query: Query statement/format string
:param parameters: Optional dictionary used to format the query
:param settings: Optional dictionary of ClickHouse settings (key/string values)
:param use_strings: Convert ClickHouse String type to Arrow string type (instead of binary)
:param external_data: ClickHouse "external data" to send with query
:param transport_settings: Optional dictionary of transport level settings (HTTP headers, etc.)
:return: PyArrow.Table
"""
check_arrow()
self._add_integration_tag("arrow")
settings = self._update_arrow_settings(settings, use_strings)
return to_arrow(
self.raw_query(
query,
parameters,
settings,
fmt="Arrow",
external_data=external_data,
transport_settings=transport_settings,
)
)
def query_arrow_stream(
self,
query: str,
parameters: Sequence | dict[str, Any] | None = None,
settings: dict[str, Any] | None = None,
use_strings: bool | None = None,
external_data: ExternalData | None = None,
transport_settings: dict[str, str] | None = None,
) -> StreamContext:
"""
Query method that returns the results as a stream of Arrow tables
:param query: Query statement/format string
:param parameters: Optional dictionary used to format the query
:param settings: Optional dictionary of ClickHouse settings (key/string values)
:param use_strings: Convert ClickHouse String type to Arrow string type (instead of binary)
:param external_data: ClickHouse "external data" to send with query
:param transport_settings: Optional dictionary of transport level settings (HTTP headers, etc.)
:return: Generator that yields a PyArrow.Table for per block representing the result set
"""
check_arrow()
self._add_integration_tag("arrow")
settings = self._update_arrow_settings(settings, use_strings)
return to_arrow_batches(
cast(
io.IOBase,
self.raw_stream(
query,
parameters,
settings,
fmt="ArrowStream",
external_data=external_data,
transport_settings=transport_settings,
),
)
)
def query_df_arrow(
self,
query: str,
parameters: Sequence | dict[str, Any] | None = None,
settings: dict[str, Any] | None = None,
use_strings: bool | None = None,
external_data: ExternalData | None = None,
transport_settings: dict[str, str] | None = None,
dataframe_library: str = "pandas",
) -> pandas.DataFrame | polars.DataFrame:
"""
Query method using the ClickHouse Arrow format to return a DataFrame
with PyArrow dtype backend. This provides better performance and memory efficiency
compared to the standard query_df method, though fewer output formatting options.
:param query: Query statement/format string
:param parameters: Optional dictionary used to format the query
:param settings: Optional dictionary of ClickHouse settings (key/string values)
:param use_strings: Convert ClickHouse String type to Arrow string type (instead of binary)
:param external_data: ClickHouse "external data" to send with query
:param transport_settings: Optional dictionary of transport level settings (HTTP headers, etc.)
:param dataframe_library: Library to use for DataFrame creation ("pandas" or "polars")
:return: DataFrame (pandas or polars based on dataframe_library parameter)
"""
check_arrow()
if dataframe_library == "pandas":
check_pandas()
self._add_integration_tag("pandas")
def converter(table: pyarrow.Table) -> pandas.DataFrame:
table = _apply_arrow_tz_policy(table, self.tz_mode)
return table.to_pandas(types_mapper=options.pd.ArrowDtype, safe=False)
elif dataframe_library == "polars":
check_polars()
self._add_integration_tag("polars")
def converter(table: pyarrow.Table) -> polars.DataFrame: # type: ignore[misc]
table = _apply_arrow_tz_policy(table, self.tz_mode)
return options.pl.from_arrow(table)
else:
raise ValueError(f"dataframe_library must be 'pandas' or 'polars', got '{dataframe_library}'")
arrow_table = self.query_arrow(
query=query,
parameters=parameters,
settings=settings,
use_strings=use_strings,
external_data=external_data,
transport_settings=transport_settings,
)
return converter(arrow_table)
def query_df_arrow_stream(
self,
query: str,
parameters: Sequence | dict[str, Any] | None = None,
settings: dict[str, Any] | None = None,
use_strings: bool | None = None,
external_data: ExternalData | None = None,
transport_settings: dict[str, str] | None = None,
dataframe_library: str = "pandas",
) -> StreamContext:
"""
Query method that returns the results as a stream of DataFrames with PyArrow dtype backend.
Each DataFrame represents a block from the ClickHouse response.
:param query: Query statement/format string
:param parameters: Optional dictionary used to format the query
:param settings: Optional dictionary of ClickHouse settings (key/string values)
:param use_strings: Convert ClickHouse String type to Arrow string type (instead of binary)
:param external_data: ClickHouse "external data" to send with query
:param transport_settings: Optional dictionary of transport level settings (HTTP headers, etc.)
:param dataframe_library: Library to use for DataFrame creation ("pandas" or "polars")
:return: StreamContext that yields DataFrames (pandas or polars based on dataframe_library parameter)
"""
check_arrow()
if dataframe_library == "pandas":
check_pandas()
self._add_integration_tag("pandas")
def converter(table: pyarrow.Table) -> pandas.DataFrame:
table = _apply_arrow_tz_policy(table, self.tz_mode)
return table.to_pandas(types_mapper=options.pd.ArrowDtype, safe=False)
elif dataframe_library == "polars":
check_polars()
self._add_integration_tag("polars")
def converter(table: pyarrow.Table) -> polars.DataFrame: # type: ignore[misc]
table = _apply_arrow_tz_policy(table, self.tz_mode)
return options.pl.from_arrow(table)
else:
raise ValueError(f"dataframe_library must be 'pandas' or 'polars', got '{dataframe_library}'")
settings = self._update_arrow_settings(settings, use_strings)
raw_stream = self.raw_stream(
query, parameters, settings, fmt="ArrowStream", external_data=external_data, transport_settings=transport_settings
)
reader = options.arrow.ipc.open_stream(raw_stream)
def df_generator():
for batch in reader:
yield converter(batch)
return StreamContext(cast(Closable, raw_stream), df_generator())
def _update_arrow_settings(self, settings: dict[str, Any] | None, use_strings: bool | None) -> dict[str, Any]:
settings = dict_copy(settings)
if self.database:
settings["database"] = self.database
str_status = self._setting_status(arrow_str_setting)
if use_strings is None:
if str_status.is_writable and not str_status.is_set:
settings[arrow_str_setting] = "1" # Default to returning strings if possible
elif use_strings != str_status.is_set:
if not str_status.is_writable:
raise OperationalError(f"Cannot change readonly {arrow_str_setting} to {use_strings}")
settings[arrow_str_setting] = "1" if use_strings else "0"
return settings
@abstractmethod
def command(
self,
cmd: str,
parameters: Sequence | dict[str, Any] | None = None,
data: str | bytes | None = None,
settings: dict[str, Any] | None = None,
use_database: bool = True,
external_data: ExternalData | None = None,
transport_settings: dict[str, str] | None = None,
) -> str | int | Sequence[str] | QuerySummary:
"""
Client method that returns a single value instead of a result set
:param cmd: ClickHouse query/command as a python format string
:param parameters: Optional dictionary of key/values pairs to be formatted
:param data: Optional 'data' for the command (for INSERT INTO in particular)
:param settings: Optional dictionary of ClickHouse settings (key/string values)
:param use_database: Send the database parameter to ClickHouse so the command will be executed in the client
database context. Otherwise, no database will be specified with the command. This is useful for determining
the default user database
:param external_data: ClickHouse "external data" to send with command/query
:param transport_settings: Optional dictionary of transport level settings (HTTP headers, etc.)
:return: Decoded response from ClickHouse as either a string, int, or sequence of strings, or QuerySummary
if no data returned. Explicitly handled read-style commands can return an empty string for empty results.
"""
@abstractmethod
def ping(self) -> bool:
"""
Validate the connection, does not throw an Exception (see debug logs)
:return: ClickHouse server is up and reachable
"""
def insert(
self,
table: str | None = None,
data: Sequence[Sequence[Any]] | None = None,
column_names: str | Sequence[str] | None = "*",
database: str | None = None,
column_types: Sequence[ClickHouseType] | None = None,
column_type_names: Sequence[str] | None = None,
column_oriented: bool = False,
settings: dict[str, Any] | None = None,
context: InsertContext | None = None,
transport_settings: dict[str, str] | None = None,
) -> QuerySummary:
"""
Method to insert multiple rows/data matrix of native Python objects. If context is specified arguments
other than data are ignored
:param table: Target table
:param data: Sequence of sequences of Python data
:param column_names: Ordered list of column names or '*' if column types should be retrieved from the
ClickHouse table definition
:param database: Target database -- will use client default database if not specified.
:param column_types: ClickHouse column types. If set then column data does not need to be retrieved from
the server
:param column_type_names: ClickHouse column type names. If set then column data does not need to be
retrieved from the server
:param column_oriented: If true the data is already "pivoted" in column form
:param settings: Optional dictionary of ClickHouse settings (key/string values)
:param context: Optional reusable insert context to allow repeated inserts into the same table with
different data batches
:param transport_settings: Optional dictionary of transport level settings (HTTP headers, etc.)
:return: QuerySummary with summary information, throws exception if insert fails
"""
if (context is None or context.empty) and data is None:
raise ProgrammingError("No data specified for insert") from None
if context is None:
if table is None:
raise ProgrammingError("No table specified for insert") from None
context = self.create_insert_context(
table,
column_names,
database,
column_types,
column_type_names,
column_oriented,
settings,
transport_settings=transport_settings,
)
if data is not None:
if not context.empty:
raise ProgrammingError("Attempting to insert new data with non-empty insert context") from None
context.data = data
return self.data_insert(context)
def insert_df(
self,
table: str | None = None,
df=None,
database: str | None = None,
settings: dict | None = None,
column_names: Sequence[str] | None = None,
column_types: Sequence[ClickHouseType] | None = None,
column_type_names: Sequence[str] | None = None,
context: InsertContext | None = None,
transport_settings: dict[str, str] | None = None,
) -> QuerySummary:
"""
Insert a pandas DataFrame into ClickHouse. If context is specified arguments other than df are ignored
:param table: ClickHouse table
:param df: two-dimensional pandas dataframe
:param database: Optional ClickHouse database
:param settings: Optional dictionary of ClickHouse settings (key/string values)
:param column_names: An optional list of ClickHouse column names. If not set, the DataFrame column names
will be used
:param column_types: ClickHouse column types. If set then column data does not need to be retrieved from
the server
:param column_type_names: ClickHouse column type names. If set then column data does not need to be
retrieved from the server
:param context: Optional reusable insert context to allow repeated inserts into the same table with
different data batches
:param transport_settings: Optional dictionary of transport level settings (HTTP headers, etc.)
:return: QuerySummary with summary information, throws exception if insert fails
"""
check_pandas()
self._add_integration_tag("pandas")
if context is None:
if column_names is None:
column_names = df.columns
elif len(column_names) != len(df.columns):
raise ProgrammingError("DataFrame column count does not match insert_columns") from None
return self.insert(
table,
df,
column_names,
database,
column_types=column_types,
column_type_names=column_type_names,
settings=settings,
transport_settings=transport_settings,
context=context,
)
def insert_arrow(
self,
table: str,
arrow_table,
database: str | None = None,
settings: dict | None = None,
transport_settings: dict[str, str] | None = None,
) -> QuerySummary:
"""
Insert a PyArrow table DataFrame into ClickHouse using raw Arrow format
:param table: ClickHouse table
:param arrow_table: PyArrow Table object
:param database: Optional ClickHouse database
:param settings: Optional dictionary of ClickHouse settings (key/string values)
:param transport_settings: Optional dictionary of transport level settings (HTTP headers, etc.)
"""
check_arrow()
self._add_integration_tag("arrow")
full_table = table if "." in table or not database else f"{database}.{table}"
compression = self.write_compression if self.write_compression in ("zstd", "lz4") else None
column_names, insert_block = arrow_buffer(arrow_table, compression)
return self.raw_insert(full_table, column_names, insert_block, settings, "Arrow", transport_settings=transport_settings)
def insert_df_arrow(
self,
table: str,
df: pandas.DataFrame | polars.DataFrame,
database: str | None = None,
settings: dict | None = None,
transport_settings: dict[str, str] | None = None,
) -> QuerySummary:
"""
Insert a pandas DataFrame with PyArrow backend or a polars DataFrame into ClickHouse using Arrow format.
This method is optimized for DataFrames that already use Arrow format, providing
better performance than the standard insert_df method.
Validation is performed and an exception will be raised if this requirement is not met.
Polars DataFrames are natively Arrow-based and don't require additional validation.
:param table: ClickHouse table name
:param df: Pandas DataFrame with PyArrow dtype backend or Polars DataFrame
:param database: Optional ClickHouse database name
:param settings: Optional dictionary of ClickHouse settings (key/string values)
:param transport_settings: Optional dictionary of transport level settings (HTTP headers, etc.)
:return: QuerySummary with summary information, throws exception if insert fails
"""
check_arrow()
if options.pd is not None and isinstance(df, options.pd.DataFrame):
df_lib = "pandas"
elif options.pl is not None and isinstance(df, options.pl.DataFrame):
df_lib = "polars"
else:
if options.pd is None and options.pl is None:
raise ImportError("A DataFrame library (pandas or polars) must be installed to use insert_df_arrow.")
raise TypeError(f"df must be either a pandas DataFrame or polars DataFrame, got {type(df).__name__}")
if df_lib == "pandas":
non_arrow_cols = [col for col, dtype in df.dtypes.items() if not isinstance(dtype, options.pd.ArrowDtype)]
if non_arrow_cols:
raise ProgrammingError(
f"insert_df_arrow requires all columns to use PyArrow dtypes. Non-Arrow columns found: [{', '.join(non_arrow_cols)}]. "
)
try:
arrow_table = options.arrow.Table.from_pandas(df, preserve_index=False)
except Exception as e:
raise DataError(f"Failed to convert pandas DataFrame to Arrow table: {e}") from e
else:
try:
arrow_table = df.to_arrow()
except Exception as e:
raise DataError(f"Failed to convert polars DataFrame to Arrow table: {e}") from e
self._add_integration_tag(df_lib)
return self.insert_arrow(
table=table,
arrow_table=arrow_table,
database=database,
settings=settings,
transport_settings=transport_settings,
)
def create_insert_context(
self,
table: str,
column_names: str | Sequence[str] | None = None,
database: str | None = None,
column_types: Sequence[ClickHouseType] | None = None,
column_type_names: Sequence[str] | None = None,
column_oriented: bool = False,
settings: dict[str, Any] | None = None,
data: Sequence[Sequence[Any]] | None = None,
transport_settings: dict[str, str] | None = None,
) -> InsertContext:
"""
Builds a reusable insert context to hold state for a duration of an insert
:param table: Target table
:param database: Target database. If not set, uses the client default database
:param column_names: Optional ordered list of column names. If not set, all columns ('*') will be assumed
in the order specified by the table definition
:param database: Target database -- will use client default database if not specified
:param column_types: ClickHouse column types. Optional Sequence of ClickHouseType objects. If neither column
types nor column type names are set, actual column types will be retrieved from the server.
:param column_type_names: ClickHouse column type names. Specified column types by name string
:param column_oriented: If true the data is already "pivoted" in column form
:param settings: Optional dictionary of ClickHouse settings (key/string values)
:param data: Initial dataset for insert
:param transport_settings: Optional dictionary of transport level settings (HTTP headers, etc.)
:return: Reusable insert context
"""
full_table = table
if "." not in table:
if database:
full_table = f"{quote_identifier(database)}.{quote_identifier(table)}"
else:
full_table = quote_identifier(table)
column_defs: list[ColumnDef] = []
if column_types is None and column_type_names is None:
describe_result = self.query(f"DESCRIBE TABLE {full_table}", settings=settings)
column_defs = [
ColumnDef(**row) for row in describe_result.named_results() if row["default_type"] not in ("ALIAS", "MATERIALIZED")
]
if column_names is None or isinstance(column_names, str) and column_names == "*":
column_names = [cd.name for cd in column_defs]
column_types = [cd.ch_type for cd in column_defs]
elif isinstance(column_names, str):
column_names = [column_names]
if len(column_names) == 0:
raise ValueError("Column names must be specified for insert")
if not column_types:
if column_type_names:
column_types = [get_from_name(name) for name in column_type_names]
else:
column_map = {d.name: d for d in column_defs}
try:
column_types = [column_map[name].ch_type for name in column_names]
except KeyError as ex:
raise ProgrammingError(f"Unrecognized column {ex} in table {table}") from None
if len(column_names) != len(column_types):
raise ProgrammingError("Column names do not match column types") from None
return InsertContext(
full_table,
column_names,
column_types,
column_oriented=column_oriented,
settings=settings,
transport_settings=transport_settings,
data=data,
)
def min_version(self, version_str: str) -> bool:
"""
Determine whether the connected server is at least the submitted version
For Altinity Stable versions like 22.8.15.25.altinitystable
the last condition in the first list comprehension expression is added
:param version_str: A version string consisting of up to 4 integers delimited by dots
:return: True if version_str is greater than the server_version, False if less than
"""
try:
server_parts = [int(x) for x in (self.server_version or "").split(".") if x.isnumeric()]
server_parts.extend([0] * (4 - len(server_parts)))
version_parts = [int(x) for x in version_str.split(".")]
version_parts.extend([0] * (4 - len(version_parts)))
except ValueError:
logger.warning(
"Server %s or requested version %s does not match format of numbers separated by dots", self.server_version, version_str
)
return False
for x, y in zip(server_parts, version_parts):
if x > y:
return True
if x < y:
return False
return True
def _add_integration_tag(self, name: str) -> None:
"""Transport hook to surface 3rd party lib integration info (default: no-op)."""
return
@abstractmethod
def data_insert(self, context: InsertContext) -> QuerySummary:
"""
Subclass implementation of the data insert
:context: InsertContext parameter object
:return: No return, throws an exception if the insert fails
"""
@abstractmethod
def raw_insert(
self,
table: str,
column_names: Sequence[str] | None = None,
insert_block: str | bytes | Generator[bytes, None, None] | BinaryIO | None = None,
settings: dict | None = None,
fmt: str | None = None,
compression: str | None = None,
transport_settings: dict[str, str] | None = None,
) -> QuerySummary:
"""
Insert data already formatted in a bytes object
:param table: Table name (whether qualified with the database name or not)
:param column_names: Sequence of column names
:param insert_block: Binary or string data already in a recognized ClickHouse format
:param settings: Optional dictionary of ClickHouse settings (key/string values)
:param fmt: Valid clickhouse format
:param compression: Recognized ClickHouse `Accept-Encoding` header compression value
:param transport_settings: Optional dictionary of transport level settings (HTTP headers, etc.)
"""
@abstractmethod
def close(self) -> None:
"""
Subclass implementation to close the connection to the server/deallocate the client
"""
@abstractmethod
def close_connections(self) -> None:
"""
Subclass implementation to disconnect all "re-used" client connections
"""
def _context_query(self, lcls: dict, **overrides):
kwargs = lcls.copy()
kwargs.pop("self")
kwargs.update(overrides)
return self._query_with_context(self.create_query_context(**kwargs))
def __enter__(self) -> Client:
return self
def __exit__(self, exc_type, exc_value, exc_traceback) -> None:
self.close()