CData Python Connector for Bitbucket

Build 24.0.9060

Reflecting Metadata

SQLAlchemy can act as an Object-relational Map (ORM). This enables you to treat records of a database table as instantiable records. To leverage this functionality, you must reflect the underlying metadata in one of the following ways.

Note: The following examples employ SQLAlchemy 1.4.

Modeling Data Using a Mapping Class

Use "sqlalchemy.ext.declarative.declarative_base" to declare a mapping class for the table you wish to model in the ORM. A known table in the data model is modeled either partially or completely, as shown in the following example:
from sqlalchemy.ext.declarative import declarative_base
Base = declarative_base()
class Issues(Base):
	__tablename__ = "Issues"
	Id = Column(String, primary_key=True)
	Title = Column(String)
	ContentRaw = Column(String)

Automatically Reflecting Metadata

Rather than mapping tables manually, SQLAlchemy can discover the metadata for one or more tables automatically. To accomplish this across the entire data model, use automap_base:
from sqlalchemy import MetaData
from sqlalchemy.ext.automap import automap_base
meta = MetaData()
abase = automap_base(metadata=meta)
abase.prepare(autoload_with=engine)
Issues = abase.classes.Issues

You can also reflect a single table with an inspector. When reflecting this way, providing a list of specific columns to map is optional:

from sqlalchemy import MetaData, Table
from sqlalchemy import inspect
meta = MetaData()
insp = inspect(engine)
Issues_table = Table("Issues", meta)
insp.reflect_table(Issues_table, ["Id","ContentRaw"])

Copyright (c) 2024 CData Software, Inc. - All rights reserved.
Build 24.0.9060