mirror of
https://github.com/hwchase17/langchain
synced 2024-11-18 09:25:54 +00:00
125 lines
4.6 KiB
Python
125 lines
4.6 KiB
Python
from __future__ import annotations
|
|
|
|
from typing import Any, Dict, Iterator, List, Optional, Tuple
|
|
|
|
from langchain_core.documents import Document
|
|
|
|
from langchain_community.document_loaders.base import BaseLoader
|
|
|
|
|
|
class SnowflakeLoader(BaseLoader):
|
|
"""Load from `Snowflake` API.
|
|
|
|
Each document represents one row of the result. The `page_content_columns`
|
|
are written into the `page_content` of the document. The `metadata_columns`
|
|
are written into the `metadata` of the document. By default, all columns
|
|
are written into the `page_content` and none into the `metadata`.
|
|
|
|
"""
|
|
|
|
def __init__(
|
|
self,
|
|
query: str,
|
|
user: str,
|
|
password: str,
|
|
account: str,
|
|
warehouse: str,
|
|
role: str,
|
|
database: str,
|
|
schema: str,
|
|
parameters: Optional[Dict[str, Any]] = None,
|
|
page_content_columns: Optional[List[str]] = None,
|
|
metadata_columns: Optional[List[str]] = None,
|
|
):
|
|
"""Initialize Snowflake document loader.
|
|
|
|
Args:
|
|
query: The query to run in Snowflake.
|
|
user: Snowflake user.
|
|
password: Snowflake password.
|
|
account: Snowflake account.
|
|
warehouse: Snowflake warehouse.
|
|
role: Snowflake role.
|
|
database: Snowflake database
|
|
schema: Snowflake schema
|
|
parameters: Optional. Parameters to pass to the query.
|
|
page_content_columns: Optional. Columns written to Document `page_content`.
|
|
metadata_columns: Optional. Columns written to Document `metadata`.
|
|
"""
|
|
self.query = query
|
|
self.user = user
|
|
self.password = password
|
|
self.account = account
|
|
self.warehouse = warehouse
|
|
self.role = role
|
|
self.database = database
|
|
self.schema = schema
|
|
self.parameters = parameters
|
|
self.page_content_columns = (
|
|
page_content_columns if page_content_columns is not None else ["*"]
|
|
)
|
|
self.metadata_columns = metadata_columns if metadata_columns is not None else []
|
|
|
|
def _execute_query(self) -> List[Dict[str, Any]]:
|
|
try:
|
|
import snowflake.connector
|
|
except ImportError as ex:
|
|
raise ImportError(
|
|
"Could not import snowflake-connector-python package. "
|
|
"Please install it with `pip install snowflake-connector-python`."
|
|
) from ex
|
|
|
|
conn = snowflake.connector.connect(
|
|
user=self.user,
|
|
password=self.password,
|
|
account=self.account,
|
|
warehouse=self.warehouse,
|
|
role=self.role,
|
|
database=self.database,
|
|
schema=self.schema,
|
|
parameters=self.parameters,
|
|
)
|
|
try:
|
|
cur = conn.cursor()
|
|
cur.execute("USE DATABASE " + self.database)
|
|
cur.execute("USE SCHEMA " + self.schema)
|
|
cur.execute(self.query, self.parameters)
|
|
query_result = cur.fetchall()
|
|
column_names = [column[0] for column in cur.description]
|
|
query_result = [dict(zip(column_names, row)) for row in query_result]
|
|
except Exception as e:
|
|
print(f"An error occurred: {e}") # noqa: T201
|
|
query_result = []
|
|
finally:
|
|
cur.close()
|
|
return query_result
|
|
|
|
def _get_columns(
|
|
self, query_result: List[Dict[str, Any]]
|
|
) -> Tuple[List[str], List[str]]:
|
|
page_content_columns = (
|
|
self.page_content_columns if self.page_content_columns else []
|
|
)
|
|
metadata_columns = self.metadata_columns if self.metadata_columns else []
|
|
if page_content_columns is None and query_result:
|
|
page_content_columns = list(query_result[0].keys())
|
|
if metadata_columns is None:
|
|
metadata_columns = []
|
|
return page_content_columns or [], metadata_columns
|
|
|
|
def lazy_load(self) -> Iterator[Document]:
|
|
query_result = self._execute_query()
|
|
if isinstance(query_result, Exception):
|
|
print(f"An error occurred during the query: {query_result}") # noqa: T201
|
|
return []
|
|
page_content_columns, metadata_columns = self._get_columns(query_result)
|
|
if "*" in page_content_columns:
|
|
page_content_columns = list(query_result[0].keys())
|
|
for row in query_result:
|
|
page_content = "\n".join(
|
|
f"{k}: {v}" for k, v in row.items() if k in page_content_columns
|
|
)
|
|
metadata = {k: v for k, v in row.items() if k in metadata_columns}
|
|
doc = Document(page_content=page_content, metadata=metadata)
|
|
yield doc
|