Perform basic operations on a Schema in PyODPS - MaxCompute

Schemas let you classify tables, resources, and functions within a MaxCompute project into finer-grained namespaces, giving you more granular control over data organization and access within a single project.

How schemas work

In MaxCompute, a schema sits between a project and its objects. The object hierarchy is: project → schema → tables/resources/functions.

After you enable the schema feature, all objects accessible to a MaxCompute entry object are placed in the schema named DEFAULT. To work with objects in a different schema, specify the target schema when you initialize the entry object or when you call an operation method.

Prerequisites

Before you begin, ensure that you have:

Enabled the schema feature for your MaxCompute project. For details, see Schema-related operations.
Set up a runtime environment. PyODPS runs on a PyODPS node in DataWorks or on an on-premises machine:
- DataWorks: Create a PyODPS 2 node or a PyODPS 3 node. For details, see Use PyODPS in DataWorks.
- On-premises machine: Install PyODPS and initialize the MaxCompute entry object.

Create a schema

schema = o.create_schema("schema_name")
print(schema)

Delete a schema

schema = o.delete_schema("schema_name")

List schemas

To list all schemas in the current project:

for schema in o.list_schemas():
    print(schema)

Work with objects in a specific schema

Initialize the entry object for a schema

To operate on objects in a schema other than DEFAULT, pass the schema parameter when initializing the ODPS entry object.

import os
from odps import ODPS

# Store your credentials in environment variables — do not hardcode AccessKey ID or AccessKey Secret.
o = ODPS(
    os.getenv('ALIBABA_CLOUD_ACCESS_KEY_ID'),
    os.getenv('ALIBABA_CLOUD_ACCESS_KEY_SECRET'),
    project='<your-default-project>',
    endpoint='<your-end-point>',
    schema='<your-schema-name>',
)

Replace the following placeholders with your actual values:

Placeholder	Description
`<your-default-project>`	The name of your MaxCompute project.
`<your-end-point>`	The endpoint of your MaxCompute project, based on the region and network connection method you selected. For details, see Endpoints. An invalid endpoint causes an error when you access MaxCompute.
`<your-schema-name>`	The name of the schema.

Specify a schema for individual operations

Pass schema directly to operation methods to target a specific schema without rebinding the entry object.

# List all tables in test_schema.
for table in o.list_tables(schema='schema_name'):
    print(table)

Specify a default schema for SQL statements

Pass default_schema to execute_sql to set the schema context for a single SQL statement.

o.execute_sql("SELECT * FROM dual", default_schema="schema_name")