# # 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 string import typing from typing import Any, Optional, List, Tuple, Sequence, Mapping import uuid if typing.TYPE_CHECKING: from pyspark.sql import SparkSession, DataFrame from pyspark.sql.utils import get_lit_sql_str from pyspark.errors import PySparkValueError class SQLStringFormatter(string.Formatter): """ A standard ``string.Formatter`` in Python that can understand PySpark instances with basic Python objects. This object has to be clear after the use for single SQL query; cannot be reused across multiple SQL queries without cleaning. """ def __init__(self, session: "SparkSession") -> None: self._session: "SparkSession" = session self._temp_views: List[Tuple[DataFrame, str]] = [] def get_field(self, field_name: str, args: Sequence[Any], kwargs: Mapping[str, Any]) -> Any: obj, first = super().get_field(field_name, args, kwargs) return self._convert_value(obj, field_name), first def _convert_value(self, val: Any, field_name: str) -> Optional[str]: """ Converts the given value into a SQL string. """ from py4j.java_gateway import is_instance_of from pyspark import SparkContext from pyspark.sql import Column, DataFrame, SparkSession if isinstance(val, Column): jsession = SparkSession.active()._jsparkSession jexpr = jsession.expression(val._jc) assert SparkContext._gateway is not None gw = SparkContext._gateway if is_instance_of( gw, jexpr, "org.apache.spark.sql.catalyst.analysis.UnresolvedAttribute" ) or is_instance_of( gw, jexpr, "org.apache.spark.sql.catalyst.expressions.AttributeReference" ): return jexpr.sql() else: raise PySparkValueError( errorClass="VALUE_NOT_PLAIN_COLUMN_REFERENCE", messageParameters={"val": str(val), "field_name": field_name}, ) elif isinstance(val, DataFrame): for df, n in self._temp_views: if df is val: return n df_name = "_pyspark_%s" % str(uuid.uuid4()).replace("-", "") self._temp_views.append((val, df_name)) val.createOrReplaceTempView(df_name) return df_name elif isinstance(val, str): return get_lit_sql_str(val) else: return val def clear(self) -> None: for _, n in self._temp_views: self._session.catalog.dropTempView(n) self._temp_views = []