mirror of
https://github.com/hwchase17/langchain
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01c2f27ffa
- **Description:** I removed two queries to the database and left just one whose results were formatted afterward into other type of schema (avoided two calls to DB) - **Issue:** / - **Dependencies:** / - **Twitter handle:** @supe_katarina
72 lines
2.5 KiB
Python
72 lines
2.5 KiB
Python
from langchain_community.graphs.neo4j_graph import Neo4jGraph
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SCHEMA_QUERY = """
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CALL llm_util.schema("raw")
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YIELD *
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RETURN *
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"""
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class MemgraphGraph(Neo4jGraph):
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"""Memgraph wrapper for graph operations.
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*Security note*: Make sure that the database connection uses credentials
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that are narrowly-scoped to only include necessary permissions.
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Failure to do so may result in data corruption or loss, since the calling
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code may attempt commands that would result in deletion, mutation
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of data if appropriately prompted or reading sensitive data if such
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data is present in the database.
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The best way to guard against such negative outcomes is to (as appropriate)
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limit the permissions granted to the credentials used with this tool.
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See https://python.langchain.com/docs/security for more information.
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"""
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def __init__(
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self, url: str, username: str, password: str, *, database: str = "memgraph"
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) -> None:
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"""Create a new Memgraph graph wrapper instance."""
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super().__init__(url, username, password, database=database)
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def refresh_schema(self) -> None:
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"""
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Refreshes the Memgraph graph schema information.
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"""
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db_structured_schema = self.query(SCHEMA_QUERY)[0].get("schema")
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assert db_structured_schema is not None
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self.structured_schema = db_structured_schema
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# Format node properties
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formatted_node_props = []
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for node_name, properties in db_structured_schema["node_props"].items():
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formatted_node_props.append(
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f"Node name: '{node_name}', Node properties: {properties}"
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)
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# Format relationship properties
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formatted_rel_props = []
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for rel_name, properties in db_structured_schema["rel_props"].items():
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formatted_rel_props.append(
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f"Relationship name: '{rel_name}', "
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f"Relationship properties: {properties}"
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)
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# Format relationships
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formatted_rels = [
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f"(:{rel['start']})-[:{rel['type']}]->(:{rel['end']})"
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for rel in db_structured_schema["relationships"]
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]
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self.schema = "\n".join(
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[
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"Node properties are the following:",
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*formatted_node_props,
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"Relationship properties are the following:",
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*formatted_rel_props,
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"The relationships are the following:",
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*formatted_rels,
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]
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)
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