Source code for airflow.providers.amazon.aws.hooks.redshift_sql

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from __future__ import annotations

import redshift_connector
from redshift_connector import Connection as RedshiftConnection
from sqlalchemy import create_engine
from sqlalchemy.engine.url import URL

from airflow.compat.functools import cached_property
from airflow.providers.common.sql.hooks.sql import DbApiHook


[docs]class RedshiftSQLHook(DbApiHook): """ Execute statements against Amazon Redshift, using redshift_connector This hook requires the redshift_conn_id connection. :param redshift_conn_id: reference to :ref:`Amazon Redshift connection id<howto/connection:redshift>` .. note:: get_sqlalchemy_engine() and get_uri() depend on sqlalchemy-amazon-redshift """
[docs] conn_name_attr = "redshift_conn_id"
[docs] default_conn_name = "redshift_default"
[docs] conn_type = "redshift"
[docs] hook_name = "Amazon Redshift"
[docs] supports_autocommit = True
@staticmethod
[docs] def get_ui_field_behaviour() -> dict: """Returns custom field behavior""" return { "hidden_fields": [], "relabeling": {"login": "User", "schema": "Database"},
} @cached_property
[docs] def conn(self): return self.get_connection(self.redshift_conn_id) # type: ignore[attr-defined]
def _get_conn_params(self) -> dict[str, str | int]: """Helper method to retrieve connection args""" conn = self.conn conn_params: dict[str, str | int] = {} if conn.login: conn_params["user"] = conn.login if conn.password: conn_params["password"] = conn.password if conn.host: conn_params["host"] = conn.host if conn.port: conn_params["port"] = conn.port if conn.schema: conn_params["database"] = conn.schema return conn_params
[docs] def get_uri(self) -> str: """Overrides DbApiHook get_uri to use redshift_connector sqlalchemy dialect as driver name""" conn_params = self._get_conn_params() if "user" in conn_params: conn_params["username"] = conn_params.pop("user") # Compatibility: The 'create' factory method was added in SQLAlchemy 1.4 # to replace calling the default URL constructor directly. create_url = getattr(URL, "create", URL) return str(create_url(drivername="redshift+redshift_connector", **conn_params))
[docs] def get_sqlalchemy_engine(self, engine_kwargs=None): """Overrides DbApiHook get_sqlalchemy_engine to pass redshift_connector specific kwargs""" conn_kwargs = self.conn.extra_dejson if engine_kwargs is None: engine_kwargs = {} if "connect_args" in engine_kwargs: engine_kwargs["connect_args"] = {**conn_kwargs, **engine_kwargs["connect_args"]} else: engine_kwargs["connect_args"] = conn_kwargs return create_engine(self.get_uri(), **engine_kwargs)
[docs] def get_table_primary_key(self, table: str, schema: str | None = "public") -> list[str] | None: """ Helper method that returns the table primary key :param table: Name of the target table :param schema: Name of the target schema, public by default :return: Primary key columns list """ sql = """ select kcu.column_name from information_schema.table_constraints tco join information_schema.key_column_usage kcu on kcu.constraint_name = tco.constraint_name and kcu.constraint_schema = tco.constraint_schema and kcu.constraint_name = tco.constraint_name where tco.constraint_type = 'PRIMARY KEY' and kcu.table_schema = %s and kcu.table_name = %s """ pk_columns = [row[0] for row in self.get_records(sql, (schema, table))] return pk_columns or None
[docs] def get_conn(self) -> RedshiftConnection: """Returns a redshift_connector.Connection object""" conn_params = self._get_conn_params() conn_kwargs_dejson = self.conn.extra_dejson conn_kwargs: dict = {**conn_params, **conn_kwargs_dejson} return redshift_connector.connect(**conn_kwargs)

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