使用 psycopg 連線集區連線

建立 SQLAlchemy 連線集區,使用 psycopg 資料庫驅動程式連線至執行個體。使用 AlloyDB 連接器可處理安全驗證和加密,簡化連線管理作業。

程式碼範例

Python

如要向 AlloyDB 進行驗證,請設定應用程式預設憑證。 詳情請參閱「為本機開發環境設定驗證機制」。

import sqlalchemy

from google.cloud.alloydbconnector import Connector


def create_sqlalchemy_engine(
    inst_uri: str,
    user: str,
    password: str,
    db: str,
    refresh_strategy: str = "background",
) -> tuple[sqlalchemy.engine.Engine, Connector]:
    """Creates a connection pool for an AlloyDB instance and returns the pool
    and the connector. Callers are responsible for closing the pool and the
    connector.

    A sample invocation looks like:

        engine, connector = create_sqlalchemy_engine(
            inst_uri,
            user,
            password,
            db,
        )
        with engine.connect() as conn:
            time = conn.execute(sqlalchemy.text("SELECT NOW()")).fetchone()
            conn.commit()
            curr_time = time[0]
            # do something with query result
            connector.close()

    Args:
        instance_uri (str):
            The instance URI specifies the instance relative to the project,
            region, and cluster. For example:
            "projects/my-project/locations/us-central1/clusters/my-cluster/instances/my-instance"
        user (str):
            The database user name, e.g., postgres
        password (str):
            The database user's password, e.g., secret-password
        db (str):
            The name of the database, e.g., mydb
        refresh_strategy (Optional[str]):
            Refresh strategy for the AlloyDB Connector. Can be one of "lazy"
            or "background". For serverless environments use "lazy" to avoid
            errors resulting from CPU being throttled.
    """
    connector = Connector(refresh_strategy=refresh_strategy)

    # create SQLAlchemy connection pool
    engine = sqlalchemy.create_engine(
        "postgresql+psycopg://",
        creator=lambda: connector.connect(
            inst_uri,
            "psycopg",
            user=user,
            password=password,
            db=db,
        ),
    )
    return engine, connector

後續步驟

如要搜尋及篩選其他 Google Cloud 產品的程式碼範例,請參閱Google Cloud 範例瀏覽工具。