Class PostgresDocumentSaver (0.4.1)

PostgresDocumentSaver(
    key,
    engine: langchain_google_cloud_sql_pg.engine.PostgresEngine,
    table_name: str,
    content_column: str,
    metadata_columns: typing.List[str] = [],
    metadata_json_column: typing.Optional[str] = None,
)

A class for saving langchain documents into a PostgreSQL database table.

Methods

_aload_table_schema

_aload_table_schema() -> sqlalchemy.sql.schema.Table

Load table schema from existing table in PgSQL database.

Returns
Type	Description
`(sqlalchemy.Table)`	The loaded table.

aadd_documents

aadd_documents(docs: typing.List[langchain_core.documents.base.Document]) -> None

Save documents in the DocumentSaver table. Document’s metadata is added to columns if found or stored in langchain_metadata JSON column.

Parameter
Name	Description
`docs`	`List[langchain_core.documents.Document]` a list of documents to be saved.

adelete

adelete(docs: typing.List[langchain_core.documents.base.Document]) -> None

Delete all instances of a document from the DocumentSaver table by matching the entire Document object.

Parameter
Name	Description
`docs`	`List[langchain_core.documents.Document]` a list of documents to be deleted.