Class MSSQLEngine (0.2.0)

MSSQLEngine(engine: sqlalchemy.engine.base.Engine)

A class for managing connections to a Cloud SQL for MSSQL database.

Methods

_create_connector_engine

_create_connector_engine(
    instance_connection_name: str, database: str, user: str, password: str
) -> sqlalchemy.engine.base.Engine

Create a SQLAlchemy engine using the Cloud SQL Python Connector.

Parameters
Name	Description
`instance_connection_name`	`str` The instance connection name of the Cloud SQL instance to establish a connection to. (ex. "project-id:instance-region:instance-name")
`database`	`str` The name of the database to connect to on the Cloud SQL instance.
`user`	`str` The username to use for authentication.
`password`	`str` The password to use for authentication.

Returns
Type	Description
`(sqlalchemy.engine.Engine)`	Engine configured using the Cloud SQL Python Connector.

_load_document_table

_load_document_table(table_name: str) -> sqlalchemy.sql.schema.Table

Load table schema from existing table in MSSQL database.

Parameter
Name	Description
`table_name`	`str` The MSSQL database table name.

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

connect

connect() -> sqlalchemy.engine.base.Connection

Create a connection from SQLAlchemy connection pool.

Returns
Type	Description
`(sqlalchemy.engine.Connection)`	a single DBAPI connection checked out from the connection pool.

from_instance

from_instance(
    project_id: str, region: str, instance: str, database: str, user: str, password: str
) -> langchain_google_cloud_sql_mssql.engine.MSSQLEngine

Create an instance of MSSQLEngine from Cloud SQL instance details.

This method uses the Cloud SQL Python Connector to connect to Cloud SQL MSSQL instance using the given database credentials.

More details can be found at https://github.com/GoogleCloudPlatform/cloud-sql-python-connector#credentials

Parameters
Name	Description
`project_id`	`str` Project ID of the Google Cloud Project where the Cloud SQL instance is located.
`region`	`str` Region where the Cloud SQL instance is located.
`instance`	`str` The name of the Cloud SQL instance.
`database`	`str` The name of the database to connect to on the Cloud SQL instance.
`db_user`	`str` The username to use for authentication.
`db_password`	`str` The password to use for authentication.

Returns
Type	Description
`(MSSQLEngine)`	The engine configured to connect to a Cloud SQL instance database.

init_chat_history_table

init_chat_history_table(table_name: str) -> None

Create table with schema required for MSSQLChatMessageHistory class.

Required schema is as follows:

CREATE TABLE {table_name} (
    id INT IDENTITY(1,1) PRIMARY KEY,
    session_id NVARCHAR(MAX) NOT NULL,
    data NVARCHAR(MAX) NOT NULL,
    type NVARCHAR(MAX) NOT NULL
)

Parameter
Name	Description
`table_name`	`str` Name of database table to create for storing chat message history.

init_document_table

init_document_table(
    table_name: str,
    metadata_columns: typing.List[sqlalchemy.sql.schema.Column] = [],
    content_column: str = "page_content",
    metadata_json_column: typing.Optional[str] = "langchain_metadata",
    overwrite_existing: bool = False,
) -> None

Create a table for saving of langchain documents.

Parameters
Name	Description
`table_name`	`str` The MSSQL database table name.
`metadata_columns`	`List[sqlalchemy.Column]` A list of SQLAlchemy Columns to create for custom metadata. Optional.
`content_column`	`str` The column to store document content. Deafult: `page_content`.
`metadata_json_column`	`Optional[str]` The column to store extra metadata in JSON format. Default: `langchain_metadata`. Optional.
`overwrite_existing`	`bool` Whether to drop existing table. Default: False.