Schema¶

Schema and VirtualModule classes

Schema management for DataJoint.

This module provides the Schema class for binding Python table classes to database schemas, and utilities for schema introspection and management.

ordered_dir ¶

ordered_dir(class_)

List class attributes respecting declaration order.

Similar to the dir() built-in, but preserves attribute declaration order as much as possible.

Parameters:

Name	Type	Description	Default
`class_`	`type`	Class to list members for.	required

Returns:

Type	Description
`list[str]`	Attributes declared in class_ and its superclasses.

VirtualModule ¶

Bases: ModuleType

A virtual module representing a DataJoint schema from database tables.

Creates a Python module with table classes automatically generated from the database schema. Useful for accessing schemas without Python source.

Parameters:

Name	Type	Description	Default
`module_name`	`str`	Display name for the module.	required
`schema_name`	`str`	Database schema name.	required
`create_schema`	`bool`	If True, create the schema if it doesn't exist. Default False.	`False`
`create_tables`	`bool`	If True, allow declaring new tables. Default False.	`False`
`connection`	`Connection`	Database connection. Defaults to `dj.conn()`.	`None`
`add_objects`	`dict`	Additional objects to add to the module namespace.	`None`

Examples:

>>> lab = dj.VirtualModule('lab', 'my_lab_schema')
>>> lab.Subject.fetch()

list_schemas ¶

list_schemas(connection=None)

List all accessible schemas on the server.

Parameters:

Name	Type	Description	Default
`connection`	`Connection`	Database connection. Defaults to `dj.conn()`.	`None`

Returns:

Type	Description
`list[str]`	Names of all accessible schemas.

virtual_schema ¶

virtual_schema(schema_name, *, connection=None, create_schema=False, create_tables=False, add_objects=None)

Create a virtual module for an existing database schema.

This is the recommended way to access database schemas when you don't have the Python source code that defined them. Returns a module-like object with table classes as attributes.

Parameters:

Name	Type	Description	Default
`schema_name`	`str`	Database schema name.	required
`connection`	`Connection`	Database connection. Defaults to `dj.conn()`.	`None`
`create_schema`	`bool`	If True, create the schema if it doesn't exist. Default False.	`False`
`create_tables`	`bool`	If True, allow declaring new tables. Default False.	`False`
`add_objects`	`dict`	Additional objects to add to the module namespace.	`None`

Returns:

Type	Description
`VirtualModule`	A module-like object with table classes as attributes.

Examples:

>>> lab = dj.virtual_schema('my_lab')
>>> lab.Subject.fetch()
>>> lab.Session & "subject_id='M001'"